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JOURN AL 


OF THE 


ROYAL 
MICROSCOPICAL SOCIETY: 


CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, 


AND A SUMMARY OF CURRENT RESEARCHES RELATING TO 


ZOOLOGY AND BOTAN DW 
(principally Invertebrata and Cryptogamia), 


MICROSCOPY, &c. 


Edited by 


FRANK CRISP, LL.B. B.A, 
One of the Secretaries of the Society 
and a Vice-President and Treasurer of the Linnean Society of London ; 


WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND 


A. W. BENNETT, M.A., B.Sc., F. JEFFREY BELL, M.A., 
Lecturer on Botany at St. Thomas's Hospital, Professor of Comparative Anatonuty in King’s College, 


8. O. RIDLEY, M.A., of the British Museum, ann JOHN MAYALL, Jon., 
FELLOWS OF THE SOCIETY. 


ser. Il V OL. lye PA Rw aA: 


PUBLISHED FOR THE SOCIETY BY 


WILLIAMS & NORGATE, 
LONDON AND EDINBURGH. 
ngs) (3) De 


he 


Vir oe 


“unm Toe LY 
tne) E ene t) 2h 4-s 


=O 1903 


JAN 


Hopal Plicraseopical Society. 


(Founded in 1839. Incorporated by Royal Charter in 1866.) 


The Society was established for the communication and discussion 
of observations and discoveries (1) tending to improvements in the con- 
struction and mode of application of the Microscope, or (2) relating to 
Biological or other subjects of Microscopical Research. 

It consists of Ordinary, Honorary, and Ex-officio Fellows. 


Ordinary Fellows are elected on a Certificate of Recommendation 
signed by three Fellows, stating the names, residence, description, &c., 
of the Candidate, of whom one of the proposers must have personal 
knowledge. The Certificate is read at a Monthly Meeting, and the 
Candidate balloted for at the succeeding Meeting. 

The Annual Subscription is £2 2s., payable in advance on election, 
and subsequently on 1st January annually, with an Entrance Fee of £2 2s. 
Future payments of the former may be compounded for at any time for 
£31 10s. Fellows elected at a meeting subsequent to that in February are 
only called upon for a proportionate part of the first year’s subscription, 
and Fellows absent from the United Kingdom for a year, or perma- 
veatly residing abroad, are exempt from one-half the subscription during 
absence. 


Honorary Fellows (limited to 50), consisting of persons eminent 
in Microscopical or Biological Science, are elected on the recommendation 
of three Fellows and the approval of the Council. - 


Ex-officio Fellows (limited to 100) consist of the Presidents for 
the time being of such Societies at home and abroad as the Council may 
recommend and a Monthly Meeting approve. They are entitled to receive 
the Society’s Publications, and to exercise all other privileges of Fellows, 
except voting, but are not required to pay any Entrance Fee or Annual 
Subscription. 


_ The Council, in whom the management of the affairs of the Society 
is vested, is elected annually, and is composed of the President, four Vice- 
Presidents, Treasurer, two Secretaries, and twelve other Fellows. 


The Meetings are held on the second Wednesday in each month, 
from October to June, in the Society’s Library at King’s College, Strand, 
we (commencing at 8p.m.). Visitors are admitted by the introduction of 

ellows. 

In each Session two additional evenings are devoted to the exhibition 
of Instruments, Apparatus, and Objects of novelty or interest relating to 
the Microscope or the subjects of Microscopical Research. 


The Journal, containing the Transactions and Proceedings of the 
Society, with a Summary of Current Researches relating to Zoology and 
Botany (principally Invertebrata and Cryptogamia), Microscopy, &c., is 
published bi-monthly, and is forwarded gratis to all Ordinary and Ex- 
officio Fellows residing in countries within the Postal Union. 

The Library, with the Instruments, Apparatus, and Cabinet of 
Objects, is open for the use of Fellows on Mondays, Tuesdays, Thursdays, 
and Fridays, from 11 a.m. to 4 P.m., and on Wednesdays from 7 to 10 p.m. 
It is closed during August. 

Forms of proposal for Fellowship, and any further information, may be obtained by 


application to the Secretaries, or Assistant-Secretary, at the Library of the Society, 
King’s College, Strand, W.C. Gon 


Patron. 


HIS ROYAL HIGHNESS 
ALBERT EDWARD, PRINCE OF WALES, 
K.G., G.C.B., F.B.8., &e. 


Past-Presidents. 

Elected. 
Ricwarp Owen, C.B., M.D., D.C.L., LL.D., F.R.S....... 1840-1 
Dory END EWS. EP), WEES erp sl a Ors fm eevieie le Veh fe els a ot 1842-3 
PROMOS PETE, CSTE scons Pele lec eltuiles O¥oOe eee es 1844-5 
James Scott Bowrgpank, LL.D., F.R.S.............6. 1846-7 
Gmc, pdt eevee die ger crsiee ic ele Outs oeterle cdidel Ss 3 1848-9 
PASSE Mn AMER AVE AE) oS Yarn. oie alesse lee se sp bed sacs 1850-1 
(MORON ghACKHON, WUT OS. 5 oo isya's nisin, sib )s el w «0, 0 leberd eye 1852-3 
Witi1am Bensamin Carpenter, C.B.,M.D.,LL.D.,F.R.S. 1854-5 
Figs aN AAT TRERISD a rclie Maia a Sn sles a alin wd '6 2 0 9 67% on tesa 1856-7 
Kpwin Lanxester, M.D., LL.D., F.RS.............05 1858-9 
JOHN THOMAS Coopmnin NOR S sees cc cc ule obs eles 1860 
Roprmrt Jamus Warrants, F.BOS. ........0ccccccoues 1861-2 
amis eer, (Wek Ese oa. esl ses elm oo 1863-4 
Panes SEAMS MG NEE Bye cist a chia’. fice nia nicstnne + 503 1865-6-7-8 
Rey. JosrpoH Banorort Reape, M.A., F.RS........... 1869-70 
Wyanrram  Kerrpumm Agee. HORS... o cs ecccccccuceawe 1871-2 
Cuanuns’ Brookes Mea HUR Bi. ss ctiene. v0 ares 1873-4 
Henry Currron Sorsy, LL.D., F.R.S.............0. . 1875-6-7 
Henry James Suiacg, F.G.S....... Sides) Baha n.d aud BO lxiabedne 1878 


ion 8, bua, M.B., ¥.B.0.P., E.BS...27200. et 1879-80 


COUNCIL. 


Exzoten 8ta Frsrvary, 1882. 


qresioent, 
Pror. P. Martin Duncan, M.B., F.R.S. 


Vice-Presidents, 


Pror. F. M. Batrour, M.A., F.R.S. 

*Ropert Brarruwaire, Esq., M.D., M.R.CS., F.L.S. 
Rozert Hupson, Esq., F.R.S., F.L.S. 

*Joun Ware StEerHenson, Hsq., F.R.A.S. 


Creusurer, 
Lionet §. Bratz, Esq., M.B., F.R.C.P., F.R.S. 


Soeretaries. 


*CHARLES Stewart, Hsq., M.R.C.S., F.L.S. 
*Frank Crisp, Esq., LL.B., B.A., V.P. & Treas. LS. 


Cloelbe other Members of Council. 


Lupwie Dreyrvs, Esq. 

CuarLes JAmEs Fox, Esq. 

James GuaisHer, Hsq., F.R.S., F.R.A.S, 
J. Witiiam Grovus, Esq. 

A. DE Souza GuimaRAENs, Hsq. 

Joun EH. Inepun, Esq. 

Joun Mayatt, Esq., Jun. 

Apert D. Micnart, Esq., F.L.S. 

*Joun Minuar, Esq., L.R.C.P.Edin., F.L.S. 
Witu1am Tuomas Surroix, Esq. 
Freperiok H. Warp, Hsq., M.R.C.S. 

T. Cuarters Waits, Esq., M.R.C.S., F.L.S, 


* Members of the Publication Committee, 


CONTENTS. 


—— 


TRANSACTIONS OF THE SOCIETY— 
I.—Further Notes on British Oribatide. By A. D. Michael, 


PAGE 


E.LS., F-R.M.S. (Plates T-andII.) .. .... .. Partl 1 
II.—A New Growing or Circulation Slide. By T. Charters 

Wihite; MER CS: RIMES) s@iiow De a a ees 19 
III.—On a Hot or Cold Stage for the ea a By W. H. 

Symons, F.R.M.S., F.C.S. (Fig.2)..0 2. .. a 21 
IV.—The President’s Address, By Prof. P. Martin Dunean, M.B. 

bos Gel ante. RON BN Bot Jeadin: Gomi obKlade: got. Boulleom) ad etwan od oTZus) 


V.—On Mounting Objects in Phosphorus, and in a Solution of 
Biniodide of Mercury and Iodide of Potassium. By John 


Ware Stephenson, Vice-President R.M.S., F.R.AS. .. ,, 163 
VI.—On the Threads of Spiders’ Webs. ae John Cain 
MD; E.R.M-S.,&e.< ..-: .. 5 G0 is 170 


VII.—Note on the Spicules found in the Ambulacral Tubes of 
the Regular Echinoidea. By Professor F. Jeffrey Bell, 
MEAG HR NES: | (blatenVis) menue: te sect e Partior2 or 


VIII.—The Relation of Aperture and Power in the cone ce 


By Professor Abbe, Hon. F.R.M.S. if 300 
[X.—The Bacteria of Davaine’s Septiceemia, 1 G. F. Dowdes- 
well, M.A., F.R.MLS., F.C.8., &c. : 310 


X.—On some Micro-Organisms from ents and Hail. 
By R. L. Maddox, M.D., Hon. F.R.M.S., &... .. .. Part 4 449 


XI.—The Relation of Aperture and Power in the Microscope 


(continued). By Professor Abbe, Hon. F.R.M.S. 3 460 
XII.—Description of a Simple Plan of Imbedding Tissues, for 

Microtome Cutting, in Semi-pulped Unglazed Printing 

Paper. By B. Wills Richardson, F.R.C.S.1., Vice-Pres. 

University of Dublin Biological Association aly ate 474 
XIII—Note on the Rey. G. L. Mills’ Paper on Diatoms in 

Peruvian Guano, By F. Kitton, Hon. F.R.M.S i 476 


XIV.—Plant-Crystals. By Dr. Aser Poli. (Plate VI.) s. «> Partido 597 


XV.—On some Organisms found in the Excrement of the Domestic 
Goat and the Gcose. By R. L. cee M.D., Hon. 
F.R.M.S. (Plate VII.) Sanalies uae op do oa Jebinn 72) 


XVI.—A Further Improvement in the SeagrsosT on: Ether 
Freezing Microtome. By J. W. Groves, F.R.M.S. (Fig. 


TAG) i vs a secre eee Oo RE a RE ed ee etn 


Vili CONTENTS. 


SuUMMARY OF CURRENT RESEARCHES RELATING TO ZooLOGY AND BoTany (PRINCI- 
PALLY INVERTEBRATA AND CrypToGAmiA), Microscopy, &c., INCLUDING 
ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* 

23, 173, 314, 478, 601, 757. 
ZOOLOGY. 


A.—GENERAL, including Embryology and Histology of the Vertebrata. 


PAGE 
Photographs of the Developmental Process in Birds .. .. Part1 238 
Development of the Paired Fins of Elasmobranchs .. .. 4, 23 


Development of the Sturgeon 1. . ws. os oe 0s 24 
Development of Petromyzon Planeri .. ee, (eeu 26 
White Corpuscles\of the Blood: \*.. s,s 2s eee my 27 
Nerve-endings of Tactile Corpuscles ..  .. ede ise 28 
Distribution and Termination of Nerves in the Ciiea 0 es 29 
Influence of Food on Sex. ac ay pate 30 
Germinal Layers and Early ieosleprnmn of the Wa. -. Part2 173 
Development of Amphioxus.. .. Sues 5 cl mnees 174 
Large Nerve-fibres in Spinal Cord of Pike HO WgOOM BOON ty 295 
Germinal Layers ofthe Chick :. >. 2. | « +. Pattid alt 
Development of Lepidosteus.. ; “ 316 
Spermatogenesis in Vertebrates and Aanelida Soamitcde Set Ae 316 
Cell-structure oc Fe OM Oc Mee mate cp 317 
Theory of Amcboid Maconents oc 319 
Distinctions between Organisms and Moras a5 gfe Ok peel 4 areas 320 
Division of Embryonic Cells in the Vertebrata .. .. .. Part 4 478 
Genesis ofthe Egg in Triton 4. <. 8 «s 26 1 4 479 
RORMOAUONIOf RIOTING, “Wee cee lets, eile tem aa fhlssjablel soe Bhs, 479 
New Blood-corpuscle .. Bite Ms, Ane re Ars Tees 480 
Life and Death in the Aiendh Or ee Dg Boe cn ode ch 481 
Pelagic and Deep-Sea Fauna 1s 01 48° bs 0 ae. 483 
Symbiosis of Dissimilar Organisms .. .. « «» « Partd 601 
PECUIC ONGUNS Of |GAYIMROTUS sol se ss ss ee cae gy 602 
Spermatogenesis in Mammalia .. 1. « « « « Part6 757 
Early Changes of the Chick 3A oe AO MOY BAC. hob bs 758 
Dimensions of Histological Elements ..  .. «+ 55 762 


Influence of the External Medium on the Saline Gonetitients 
of the Blood of Aquatic Animals .. .. ss «oF o 4% 763 


B.— INVERTEBRATA. 


Fossil Organisms in Meteorites .. .. 20 at. be Path ee 
Red Pigment of Invertebrates (T SF, Pn es ne » 178 
“ Symbiosis of Animals with Plants Bad, RS ore nor, 

and Amyloid Deposits of Spongilla and Hydra .. .. Part 3 322 
Paleontological Significance of the Tracks of ae 

Lier bebr gen nto Wig Wie ge mn ai a ts pa » 324 
Lymph of Invertebrates ©‘. 2 eeeie ce de oe Nas 327 
Intracellular Digestion... .. ss «© 06 «8 08 os Part 5 602 


* The titles of the papers and notes printed in the ‘ Transactions’ and ‘ Pro- 
ceedings’ are also included here to make the classification complete. 


CONTENTS. 


Development of some Metazoa 
Symbiosis of Dissimilar Organisms 
Pelagic Fauna of Fresh-water Lakes .. 


Mollusca. 


Digestion of Ainyloids in Cephalopoda 

Proneomenia sluiteri .. 4. we 

Maturation, Fecundation and iSegnentniion of ie cam- 
pestris dos 0Dt 00. “o™ 0), 100 

Kidney of Chiton.. .. + 

Morphology of Neomenia c 

Development of the Cephalopoda .. 

Development of the Oyster 

Abortion of Reproductive Organs of Vitri: ma 

Morphology of the Amphineura : 50 

Anatomy and Classification of the Conialopoda 

Ink-Sac of Cephalopoda 00.00, «0d... 60s d=!) Od 

Sense of Colour in Cephalopoda .. ; 

“ Foot” of certain Terrestrial Gastropoda . 

Mucin of Helix pomatia 

Rhodope verani 

Nervous System of oiascat 

North-American Cephalopods 4 

Marginella and the (Boia apa) 

Vascular System of Naiades and Mi Sea 

Sexuality of the Oyster : 6 

Curious Secretion in Gesiorasem 

Olfactory Organ of Parmacella .. 

Innervation of the Mantle of Were linac : 

Differentiation of Protoplasm in Nerve-fibres of Toten 


Molluscoida. 


Deaglynnans Of Sly co 00 90 a6. ca 00 oo 
Tunicata of the * Challenger’? : 
Organization and Development of the Uscearmen: 

‘ Challenger’ Ascidians (Culeolus) bc 60, OO 
Embryonic Membranes of the Salpide G5 | pdt bo! -ad 
Modifications of the Avicularia in Bryozoa.. 

New Synascidian .. on 

Alternation of Conenttiaiee F im Deana ‘ie on 
Tesi-Cells im Ascidian Oud ., 26, 25 oso 
Embryology of the Bryozoa.. 


ING ANG AAO TER OOon Ge 
Disdaplia SOT EOEE Ve lCR 1.06 
Natural History of Dorotam! 50 0 


Development of Ganglion and Ciliated ‘Baer m Ree eset 
Development of Genital Products of Cheilostomatous Bryozoa 


Arthropoda, 


Brain of Crustacea and Insects .. 


. Part 6 


bed 


9 


ag Jeeman AL 


0 


Part 2 


7 


”? 
Part 3 


ix 


PAGE 
763 
764 
765 


30 
31 


178 
179 
180 
328 
330 
330 
331 
485 
487 
489 
489 
490 
491 
603 
604 
604 
605 
606 
766 
767 
767 
767 


32 

33 
180 
182 
182 
183 
331 
331 
491 
492 
494 
768 
768 
769 
769 


770 


CONTENTS. 


a. Insecta, 

Striated Muscle of Coleoptera and its Ner sceaaiee -» Part 1 
Terminations of the Motor Nerves in the Striated Muscles 

of Insects .. Seer Te sve. Thee 
Wings of Insects... . oe 
Structure of the Proboscis of pepe = 
Post-embryonic Development of Diptera 
Development of Adoxus vitis a 
Colouring Matter from the Willow-tree eas Be as 
Flight of Insects .. Jo | o. Bart 
Nucleus of the Salivary Cells “ the ieee of heromamete + 
Nervous System of the Larve of Diptera .. ce) es Aare 
Occident Ants 
Sensations of Sight ee = pemeeae Figs 88 au s) Part 4 
Nervous System of the Strepsiptera Eee 
Insects which injure Books . 
Formation of Galls  ..  « Seehctess ices Gee a ee 
Respiratory Movements of Pasa ee On ume eatin bt SS 
Location of Taste in Insects 
Parthenogenesis in the Bee .. 
Eye of Chloeon diptera., ..  « 
Marine Caddis-fly : 
Want of Cutaneous ees in apes pies 
Habits of Ants, Bees, and Wasps ae) oe Mee re 
Larve and Pupe of Diptera x 
Organs of Flight in Hemiptera .. .. 


8. Myriapoda. 
Diversity of Type in Ancient Myriapods .. .. .. .. Part6 


«e “- on «e ” 


” 
-- Part 6 


y. Arachnida. 
Further Notes on British Oribatide. Sage? Land JI.) .. Partl 
Liver of Spiders en 
Limulus an Arachnid .. .. ° 
Functions of the Caudal Spine of caomnis “ sl Ae 
On the Threads of Spiders’ Webs HPCE. Nobee Gop esis 
Structure of the Dermaleichide .. .. .. «2 « «= 9 
UCRO ONAN eos uate eco tos “iss cA) testis?) wap) AT hE 
Spiders Webs... 25g Wo” ed Scte "Se abe Ss. 
Anatomy of Phaienjidar = o> - ce Pare 
Scent-glands of the Gicteuconiay toes ( Thelyphonus) ee ee 
Respiratory Organs of Arachnids. Oe nae .. Partd 

Habits of Scorpions .. 

Nest-forms of the Furrow Spider : 
Parthenogenesis in the House Spider .. 
Segmentation in the Mites 
Observations on Scorpions 
Insecticolous Acari s 
Sense-hairs of the Peau oe 


“- “* -* ” 


-* o- - oe - - ” 


6. Crustacea. 


Adaptations of Limbs in Atyoida Potimirim .. .. «. Partl 


42 


CONTENTS. 


Colour-sense in Crustacea 
Germs of Artemia salina 
New and rare French Crustacea. 


(Fig. 28) 


New British Cladocera from Grasmere Lake 


The Entoniscida . 

The Bopyride 

Limulus a Crustacean ..  .. 
Segmental Organs in Isopoda 
Bopyride 


Classification of the Brain of Grutacan 


Unpaired Eye of Crustacea.. 
Blood of the Crustacea.. 


Pyloric Ampulle of Potopthaimts C Geusproen On 


Heterogeny of Daphnia 
Notodelphyide c 
Organization of Tr ilobites 
Perception of Colour by Crustacea 
Mediterranean Crustacea , 
North American Crustacea .. 

New Copepoda 

Ontogeny of resin Conard: 
Aberrant Oniscoids 


Blind Subterranean Cr seve in Rep Gennes 


Vermes. 


Origin of the Central Nervous System of the Annelida 


Swim-bladder-like Organs in Annelids 


Development of Polygordius and Saccocirrus od 
Termination of Nerves in the Voluntary Muscles of the 


Leech.. 
The Echiurida 


x1 

PAGE 

o« Part] 43 
Paulin tr as he 
. Part 2 186 
a a i 

i aS 


188 


sa) S55 
ation sou 


RESET 
338 


50 op 
.. Part 4 503 


Segmental Organs and Genital Gland of some cl Siniediaoe 
Anatomy and peat of spores nudus 


Sternaspis ...  .. . 

Hamingia glacialis  .. .. « 
Echinorhynchus ..  .. 2 «. 
Proscolex of Bilharzia hematobia 
Nervous System of Cestoda .. 2c 
Development of the Ovum of Velicerta 


Anatomy and Histology of Scoloplos armiger 


Parasitic Eunicid.. fe 
Development of Anguillula steno ite 
Cercaria with Caudal Sete .. 

New Type of Turbellaria 


Systematic Position of Balanoglossus .. 


Nervous System of Platyhelminthes 


Structure of Gunda segmentata, and the Ralationshins of 


the Platyhelminthes with the Celenterata and Hirudinea 


Peculiar Mode of Copulation in Marine Dendrocela .. 


Classification of the Nematohelminthes 


53 504 
3 504 
es 505 
55 506 
55 506 
508 

Part 5 615 
5 615 
es 617 
617 

Part 6 776 
9 77 
.. 778 

. Partl 44 
99 44 
” 46 
“5 46 
» 47 
3 47 
” 48 
9 48 

> 50 
9 ol 
”? 51 
oh 51 
53 

Part 2 188 
o 190 
os 191 
Ps 192 
> 192 
- 194 
= 194 
a 197 

. Part 3 340 


ae 240 


xll 


CONTENTS. 


Relations of the Platyhelminthes .. 
Entozoa confounded with Trichine 
Life- History of the Liver Fluke .. .. 
Excrétory Apparatus of Turbellaria .. 
New Parasites .. 

Tube of Stephanoceros Hichornii.. 
Chemical Composition of Tubes of Oniiphiss. 
Nematoid Hamatozoon from a Camel.. 
Development of Marine Planaria 

Eyes of Planarians 

Development of the Orthonaciaa™ 

Eyes of Rotifers .. 

Development of Annelids 


Development of the Central Nervous Systm of Arnolds - 


Coral-neefivAnnelid) Wc. ae as) ae es os 
Muscular Tissue of the Leech .. .. 4. 
Observations on the Dicyemide 
Orthonectida.. .. .. 

New Rotifer (Cupelopagis cine 
Synthetic Annelid Te, oe 4 
Elytra of Aphroditacean eaends 
Phosphorescent Organs of Tomopteris.. 
Priapulus bicaudatus ae 
Anatomy of Ankylostoma punta: 
Structure of Trematodes 

Adaptation to Environment in the Tr Gian 
Vascular Organs of Trematoda .. 

Anatomy of Cestodes 

Studies on Cestodes a5 

Liguia and Schistocephalus .. 

New Floscularia .. .. . 

Desiccation of Rotifers 


Echinodermata. 
Development of the Skeleton e the ge ee 
Asterias Sc : : 50°" Ta SE Bae ac 
Spines of Astorcided a0. ae sere Toscan as 
Nervous System of the Oninunotios sae am "OD 


American Comatule .. .. 


Note on the Spicules found in the Tha peg Tubes oft the 


regular Echinoidea, (Plate V.) .. « 
Structure of Pedicellarie .. «1 « oF 
Circulating Apparatus of Starjishes beh ox Siu) dekere 
Genital Passages of Asterias .. 1. se ee 
Histology of Temnopleuride Soe ey cou. Moat 
Anatomy of Holothurians ..  .. ss «6 oe ws 
Hybridization of Echinoidea op mock MDD, & Ad | tec 
Variation in Asterias glacialis .. 1. ws we 
Anatomy of Echinoidss,» sa: usr tyxecy ep apadh wat 
Anatomy of Spatangus purpureus cg aoe an, aC 
Development of Asterina gibbosa .. 1. 11 ws 


oe 


PAGE 


. Part 3 340 


arti: 


” 


shit» ee 
see aT tae, 


” 


. Part 4 


. ” 
eeeartio 


” 
7 


peartns 


342 
342 
344 
345 
345 
509 
509 
509 
510 
dll 
512 
618 
619 
621 
621 
621 
624 
625 
778 
779 
780 
780 
781 
782 
784 
784 
785 
786 
786 
787 
787 


55 
56 
57 
199 
199 


297 
346 
347 
348 
443 
512 
513 
513 
626 
627 
628 


CONTENTS. 


Brisinga ne 

Anatomy of Bonin tise HOLE OOS eee) hp tae 
Heteractinism in Echinodermata , 

Circulatory Apparatus of fier Echinoids 
Structure and Development of Ophiuroids .. 

Formule for Comatulide 

Holothuroidea of the Norwegian North ‘Sex cameo 
Histology of Digestive Canal of Holothuria Or 


Celenterata. 
Prodrome of the Anthozoan Fauna of Naples 
Metamorphoses of Cassiopeia borbonica .. 
Development of Geryonopsida and Eucopida 
Fission of Phialidium variabile .. 
Crambessa tagi 
Seaual Cells of Ey NE KEE 
Spermatozoa of Hydrozoa .. oC 
Characters of Stinging-Cells of Colennata 
Development of the Celenterata .. 
Nervous System of Hydroid Polyps 
Remarkable Organ in Eudendrium ramosum 
Siphonophora of the Bay of Naples : 
Ctenophora of the Bay of Naples 
Clavularia prolifera .. . 5 ce 
Development of Calcareous Skeleton i Astonoiies 
Development of Lquorea “ie 
Tissues of Siphonophora 1. 1s a 
Development of Tubularia cristata 
American Acalephe .. 1. as 
Sense of Smell in Actinie .. .. 
Studies on Celenterates Bo Nite OE 
Organization of Hydroid Polyps. Beh nese 
JUVE eH oe 5 Rac gee 
Vital Phenomena of ice 
Ovaries of Actinie dei Geeh Wiese! wise 
Skeleton of Madrepores «. se +s ae 
Studies on Gorgoniad@.. 2. «s . 26 «= 
Development of Aleyonaria .. 1» 11 se 


Porifera. 

Attempt to Apply Shorthand to Sponges eet 
Sponges of the Gulf of Triest 12 «+ «1 «+ 
Spongiophaga in Fresh-water Sponges Bee Mec 
New Eresh-water Sponges 2. «5 «1. o* ae 0» 
Hybridization in Fresh-water Sponges sii ao 

BOTULG | SP ONGCS: mee ements canes sie a soa sa 
Manual of the Sponges Ae ACC ek tence No: 
Development of Reniera filigrana es er 
New Fresh-water Sponges 1. 1» +» « oF 


Protozoa. 
Flagellata 


pLAaris 


~ 39 
. Part 6 


X1ii 


PAGE 
631 
632 
788 
789 
789 
791 
791 
792 


XIV 


CONTENTS. 


Infusoria Parasitic in Cephalopods 
Parasites of the Echiurida .. a 
Symbiosis of Lower Animals with Plants e 
New Sub-class of Sed rica aaa 
Skeleton of the Radiolaria .. « .. 
Recent Researches on the Heliozoa 
Dimorpha mutans... 


Contributions to the Knowiad ie of the Deane: 


Protozoa of the White Sea .... 
Organization of the Cilio-flagellata 
Infusorian with Spicular Skeleton 
Contractile Vacuole of Vorticella 
Geographical Distribution of Rhizopoda 
Classification of the Gregarinida 
Psorospermia in Man .. 
Myxosporidia 

Morphology of Eee 

Eozoon Canadense 

De Lanessan’s Protozoa as 
Kents Manual of the Rees Bc 
Flagellata : 


Cell-parasite of Prope! Blood ap Spleen (Drepantiom 


ranarum) . 
Development of Peeper 
New Gregarines 
Ciliation of the a eraious Tess 
Species of Vorticelle she 
Acinetide 
New Type of Pordattaciis oparnsnefora 


Bacterium rubescens Lank. = Monas Ohkenii Ehr. 


Biitschli’s Protozoa y 6 

New Ciliate Infusorian Bee. “ica 6c 
Actinophrys sol : 

Nuclei of Pee 

Parasitic Protozoa 

Intestinal Parasites of Oy tig 


BOTANY. 


laieTii) 5 


) Partie 


A.—GENERAL, including Embryology and Histology of the Phanerogamia. 


Origin of the Embryo-sac and Functions of the Antipodal 


CHI ca loch 0b Si ice 
Palveniamas in Ramee 
Resistance of Seeds to extreme Cold 


Mechanical Contrivances for the Dispersion of Seeds te 


Fruits 


Chemical Difference feneen Bead. ih ieee. Prien a8 =p 


Energy of Growth of the Apical Cell and ae the ae 


Segments .... 
Action of Nitrous Onide on Vegetable Cie 
Chlorophyll and the Cell-Nucleus .. ae 


CONTENTS. XV 
PAGE 

Influence of Warmth of the Soil on the Cell- HON Ce of 
Plants : : liter . Part1l 70 
Growth of Staacrgrains by Tiivccoceatap, £ 70 
Collenchyma be ” 71 
Epidermis of the icin of Serspecent: ane) Darling Gena 9% 72 
Laticiferous Vessels BRN AA ONG are sia ree eh ty Ibis + 73 
Epidermal System of Roots .. 73 
Passage from the Root to the Stem Ms 74 
Causes of Eccentric Growth Pr 74 
Hydrotropism of Roots., .. Fe 74 
Cause of the Swelling of Root _fibres 3 75 
Frank’s Diseases of Plants .. ..  . o o0 oc 75 
Free Cell-formation in the Embryo-sac of Wnoscornns 5 Part 2 214 
Fertilization of Apocynacee 5 215 
Cross-fertilization and Distribution of ‘Seeds <i 215 
Swelling of the Pea bo. 100 60 1) 216 
Aril of Ravenala .. te 5 216 
Structure and Mechanics of iseomata 50 oF 216 
Callus-plates of Sieve-tubes .. as 5p 218 
Phyllomic Nectar Glands in Poplars .. & 219 
Histology of Urticacee.. .. ..  s. 219 
Structure of Podostemonaceee - 220 
Pitchers of Cephalotus follicularis BB 220 
Action of Light on Vegetation % 220 
Production of Heat by Intramolecular Respiration iS 221 
Physiological Functions of Transpiration os 221 
Metastasis 9 221 
Phosphorescence in Plants : : 5 222 
Transformation of Starch .. ..  .. OO 53 222 
Occurrence of Allantoin in the Vegetable Ornanisin . 223 
Lacretion of Water on the Surface of Nectaries 3 223 

Determination of the Activity oe Assimilation by the Bubbles 
given off under water 0 Be Sep Wel Mcctn Beets 223 
Detmer’s Vegetable Physiology Cees 223 
Chemical Difference between Dead and fae iprereniaerie Part 3 361 
Occurrence of Aldehydes in Chlorophyllaceous Plants 7 361 
Organ not hitherto described in the Vegetable Embryo 3 361 
Studies of Protoplasm .. Fe 362 
Composition of the Protoplasm of Zithalium saptiouins 3 362 
Properties of the Protoplasm in Urtica urens ..  .. 3 363 
Fertilization of Salvia splendens 363 
Reproductive Organs of Loranthacee .. ie 5 363 
Structure and Mode of Formation of Gagaecionents acid bialaeny 364 
Cell-nucleus in the Mother-cells of the Pollen of Liliacee ..  ,, 366 
Crystalloids in the Cell-nuclei of Pinguicula and Utricularia  ,, 366 
Cystoliths in Momordica HOM MLGCME MA Mir itd aici. ho a 367 
Sphero-crystals ots 367 
Structure of Starch-grains .. i" 368 
Assimilating Tissue... 2c > 368 
Fibrovascular Bundles of Monocor aeons a * 370 


XVl CONTENTS. 


PAGE 
Sieve-Tubes ..  .. 50 co co coe pomeciind). Sg 
Structure and Danan of Stomata opt no cok oon oo |) cp 372 
Stomata of Stapelia ..  .. $4 372 
Influences of External Forces on aie Direotion a Gr ue % 372 
Water Distribution in Plants -.. . PoC nee. 373 
Causes of the Movement of Water in Pits 5qy Gob gcd. 6D 373 
“ Compass-flowers”  .. a 373 
Chemical Difference ieee Dead on Living Pr saps. 

(ERG MOO) Weens en ws ie he! Gey oe (Rartitone 
Killing of Prien by Yy Va arious Saegeats Aiea oo SEO cp 522 
Apical Cell-growth in Phanerogams .. «1 «+8 08 459 523 
Development of Bordered Pits .. » 923 
Development of Tissue as a Characteristic of Grows of Plants =) 524 
Stomata of Polycolymna Stuarti are Sos 0b 524 
Properties and Mode of Formation of Dunas 6B. BE 3 525 
History of Assimilation and of the Functions of Cnorophyl + 525 
Theoretical View of the Process of Assimilation x TREY Ss 525 
First Products of Assimilation .. .. 6 of «6 « 4 526 
Absorption of Metallic Oxides by Plants .. .. 5 526 
Decomposition of Calcium carbonate in the Stem of Theat: 

VEGOnOUSSVVOOUS/t.4 tose ‘ecm ces Wrest Dich Meee eee tae | as 527 
Hypochlorin ..  .. Shi) ont Ot MOG! Orn Ok oy 528 
Latex of Euphorbia athe ttc 5 529 
Darwin's so-called “* Brain function” of the Tips of Pe a <p 529 
Aerial Cultivation of Aquatic Plants .. 1. ss «2 + 4 530 
SECHIUONOUS PELLANUS IA teat) lee) Phe! SiMepl idee Lites Siainiom te a 531 
Climbing Plants .. .. . Ege OND 6G.) ates oo 531 
Power of Movement in Plants Ao) PG. Yodo oe INO) cy 531 
Electrical Researches on Plant Forms AC AC anc 5 532 
Llectromotive Properties of the Leaf of Tone 0 6G 533 
Influence of a Galvanic Current on Growing Roots .. .. 4 533 
Plant-crystals. (Plate VI.) .. «. oe peel es hatbomoong 
Development of the Embryo and Prnaeaae BRM ic tery eeney 643 
Embryogeny of the Leguminose .. 1.) «2 un wee 644 
Development of the Ovule of Primula... .. 1. se ae 5, 647 
Homology of the Ovule.. .. Toe OOM ons lod. Ube. ir 648 
Phytoblasts and their Pacdeoadia Ag oO, Pa. Roby Mahe ie ce 649 
Formation of Pollen-tubes ..  .. Mee ae eee ery es, 649 
Cause of the Movement of Pitlenabe sayy Walt Shee Ane ies 650 
Apical Growth of the Roots of Phanerogams .. .. ss 45 650 
Pitchers of Dischidia Rafflesiana 36 8 + 651 


Influence of Light and Air on the eemeraieal aces of 

ELOie a ii SMe APU Tele kui sich Wath) Vote 2s\ ue by Yea ai” gary Trae. bay 651 
Respiration pf PuaitasNae Pras A ie Uo lee lo oh | Hea ben I A® Gey 651 
Oxalate of Lime in Plants .. 1. « Pom eaense? diss 653 
Insects and the Cross-fertilization of Fiona He os vee 653 
Structure and Movement of Protoplasm .. 1. sw Part 6 804 
Protoplasm of Compound Laticiferous Tubes .. .. +» 43 805 
Development of the Embryo-sac ..  .. eel eeeh a ee gy 805 
Development of the Embryo in Lupinus 1. we ue egg Ss 807 


CONTENTS. xvi 
PAGE 
Tomologypoy the OOule see ae eek ee a ee en oe EartG 808 
Reproductive Organs of Cyeadee nie Ee ; es 808 
Cell- and Nuclear Division in the icematon of the Pollen of 
Hemerocallis fulua ..  .. Ago Es kee 2 en 809 
Structure and Growth of the Cellar ae “f 810 
Order of Appearance of the Primary Vessels in Aerial Or fone - 812 
Collenchyma ..  «. ae Goh sce) Adi npos, tong octal Fr 812 
Stomata in a Fossil Plant Sp aon ae Saye ae! ee s 813 
Spiral Cells in Crinum and Ne enieee eT eatin, Geer els)- iss 813 
suructune of Secretory Glands <j. 2. 2s ss so ee ss 814 
Sphero-crystals ss 4. 00 OC 55 815 
Respiration of Detached Shoots Sala ee 3 815 
Physiological Functions of the Tissues of inate s 816 
Ciiloro ply ly aedeldy POC LOTT aN etnies) eeu oun es) ss 817 
Tygon Gy URGE og 6 so 6 de RO ee 818 — 
Vitality of the Chlorophyll-pigment .. «1 .. « ms 818 
Action of various Gases on Plants .2 se . «ss « 4 818 
Power of Plants to absorb Carbonic Oxide .. 1s «1 11 5 819 
HORTE AGO GE TAGTES co Bb Gk a op 819 
Function of Lime-salts bb eee SC OO) eee os 819 
Function of Resinous Substances., .. aS 820 
Change of Starch into Sugar at low cpreig tes co) “cee gp 821 
Colours of Flowers AG aah a. cer ane es atm ecole oer ise 821 
Causes of the Etiolation of Biante Oe Go ad Vad ae) 822 
Origivof Galls “ss ss 2» ve AO GAG, 4 dees aor 823 
Chemical Difference between Living HE Dead eeotpiern oe 902 
B.—CryYPToGAMia. 
Cryptogamia Vascularia. 
Prothallium and Embryo of Azolla .. .. oq. feo) dethardl YE 
Development of the Sporangia and Spores of Tene Get Creep 78 
Development of Sporangia .. .. .» os. «os «os «oe Part2 294 
Lenticels of the Marattiacee ede Pele idi comet, oid cleat cath ye 225 
Stomata in the Leaf-stalk of Filicinee oo rf 226 
Adventitious Buds on the Lamina of the Frond of Aspiras 
bulbiferum Holtetecic BE are Fe 226 
Anatomy and Classification of Sena Selhihy cht scr Moe) ess 226 
Biological Peculiarity of Azolla caroliniana .. x 227 
Relation of Nutrition to the Distribution of the Gees 
Organs on the Prothallium of Ferns .. Part 3 374 
Cell-division and Development a the > Entry of eee 
IACUSTMIS§ Hse, Aas he oe Brae? ude (ach ate 373 
Schizewace@ .. .. co Noe ee od) on, Uiahd: GBS 
Wale Fructification of Politrichien Souipoce fod, ne ec ol GE OEE 
Muscinee. 
New Genera’ op Mosses. a 210) ma et ee oe Parak 79 
Classification of Sphagnacee sail Teja, jaa ea eM sa), . las 79 
Female Receptacle of the Jungermanniee Geocalycee -. Part 2 227 
Vegetative Reproduction of Sphagnum Sahy ewibetesr | se) - Shee 228 


Ser. 2.—Vox. IT. 


b 


XVili 


CONTENTS. 


Chemical Composition of Mosses.. 11 ss as 
Branched Sporogonium ofa Moss .. . 
Influence of Light on the Thallus a Bonckantia 
Goebel’s Muscinee oe Some alunes 
Classification of Seiad bo von icon ce 
Wale Fructification of Polytrichum 


Characee. 
Cell-nucleus in Chara fetida are 
Development of the Cortex in Chara .. 


Fungi. 
Conidial Apparatus in Hydnum .. 11 
Alternation of Generations in Uredinee 
Mode of Parasitism of Puccinia Malvacearum .. 
Sterigmatocystis do. dé) ne 
Oospores of Phytophthora ceria dite: Ghee o6 
PELONOSPONAOVLICOLG aon Neel toe eel ee) inte 
Vegetation of Fungi in Oil .. 6. 20 ewe 
JENS VEOIIYRYS ou 20 6a 80 ot toe 
Ear-Fungi .. . . 50 Col yan ty os 
Insect-destroying Craptagan AON sche Lor 
Brefeld’s Schimmelpilze .. . “e 
Influence of Light on the Growth of Penicillium 
Production of Microphytes within the Egg .. 
Aitiology of Diphtheria ae oe ope 
Properties and Functions of Boaters 
Atmospheric Bacteria .. 
Pathogenous Bacillus in Drinking Water 
Connection of Diseases with Specific Bacilli 
Origin of the lowest Organisms 


Prolongation of Vegetative Activity of Choropylin Cells 


under the influence of a Boa AG moo ne 


Action of Light on Fungi... oy Wes 
Chemical Nature of the Cell-wall in Pere 
“ Mal nero” of the Vine .. «.. 2 


Roesleria hypogea parasitic on the Vine 
Didymospheria and Microthelia.. .. .. 
Peronosporee and Saprolegnice .. .. «+ as 
Fungi in Pharmaceutical Solutions .. .. « 
Vegetable Organisms in Human Uameienta a 
Saccharomyces apiculatus .. ss 46 we we 
Etiology of Malarial Fevers Sy CMC ex 
Aktinomykosis, a new Fungoid Cuttle-Disease 3 
Infection by Symptomatic Anthrax .. 


Experiments on Pasteur’s Method of Anthrax- Vaca 


Duration of Immunity from Anthrax gh sion 
New Method of Vaccination for Fowl-cholera .. 
TRADES! we (ise oes: RUT Eo eISSN Veo Mors 
Bacteria of Disodine’ s Benton 


Influence of Oxygen on the Development of ‘the eee Fungi 


PAGE 

7 wattio ust 
. Part 4 534 
a 534 
seas 535 
»» Part a'Ga5 
. Part 6 823 
Parthia 
. Part 4 535 
. Partl 80 
» 80 

” 80 

” 80 

” 81 

” 81 

- 81 

op 83 

35 83 

=n 83 

s 83 

45 87 

” 87 

9 87 

” 88 

o. : 

” 89 

= 89 

45 90 


i 93 
- Part 2 298 
» 228 

» 229 

» 229 
288 

» ) ee 

> ee 

» 284 

» 284 
ues 

» 236 

>. age 

» 288 

» 239 

» 289 


239 


. - Part 3 310 


>» Joie 


CONTENTS. x1x 


PAGE 
Chatomium ..  «. 50 ido derbanas Bis 
Completoria Shines s a Barasie on ys lesoanin of 
Ferns ie AG aon NOGTEM Or Ne ae Becca nos Conn eer 377 
Rehnvs Uscbnncates 00, 10 so nici ED Asie deleicielee | 5 378 
Destruction of Insects by Ye oiseh te ns 378 
Development of Fungi on the Outside ag Tasvie of “Hen’s 
Eggs .. +» Boy Oe Soe took Lod | van rots doe mer 378 
Biology of Bacteria a0 | A bi eitoe + 380 
Influence of Concussion on the Deneimnent of ‘the Schizo- + 382 
mycetes .. 3 382 
Experimental Pr ecction of we Bacteria of the ‘Cattle- 
distemper .. .. Siebrsleis Picea Me ciavecn “iss 382 
Bacteria of Caucasian Milk jin So Gn a6 1.00) | ode es 383 
Parasitic Organisms of Dressings .. os © « « 4 384 
Parasitic Nature of Cholera BOs Noo) Heol BO) Od. Sonn arp 384 
EOrasitismy Of, Luberculosisis.m sajei set aah lepencani se) 55 384 
Haperimental Tuberculosis oo) os 21 se ewe se gg 385 
Etiology of Tubercular Disease ..  .. 00°. gp 385 
On some Micro-organisms from iguionenor lies ‘spe Hait . Part 4 449 
Ustilaginee .. .. AEIBE OM Nor EaO0 cakes 536 
Unobserved Soieitineness in Paycomijees bo 00-00. 06 538 
Beltrania, a New Genus of Hyphomycetes.. .. .. «. 45 538 
Chemical Composition of Moulds... .. 1. 1. os ae 49 538 
Salmon Disease .. Bon ere cae ere 538 
Formation of Gonchrenisreen ¢ in Nutrient Fluids Cua ea ; 
various Proportions of Nitrogen .. a 540 
Morphology and Genetic Relationship g Pathogen 
BOCLORUD wot ayes te oeneleee cise Gels ay NGO GO) FH 541 
EGLhOG CNOUS <DOCLENU Tot, iene is eel clhl cee leaieese alse 541 
Bacterium of Charbon.. .. . arcs Robie Oo sco, OO re 541 
Connection of Bacteria with ements B05 64 00 9 60° 041 
Leucogaster, a New Genus of Hymenogastree .. .. .. Part5 654 
Parasites of the Human Har ., .. .» «2 « «2 655 
Chromogenous Schizomycete on Cooked Meat nip! cts Wa. eer 655 
New Bacterium sensitive to Light .. .. ph BA aeecr 656 
Connection of the Bacilli of Hee and of Distompe 50! G0. | Ep 657 
Diffusion of Bacteria .. .. ema BM Ont som nap 658 
Parasite of Malaria .. .. Bo) Bo! 600. Ga “ep 659 
Parasitic Character of Cases of Malaria Gore e0I" "Oa GG! oF 659 
VaccinaleMecrococcia st ea) Soap ts sci, els ncsvelesep eee, po 661 
Mucorini.. se ba... 7 661 


On some Orgartons found in the Tmarspar of the Donen 

Goat and the Goose. (Plate VII.).. .. . . . Part6 749 
Epiplasm of Ascomycetes—Glycogen of Plants... .. .. 45 824 
Agaricini.. Ba 60. ie 825 
Development of Sclerouam of Reger Galan eee s'*)) | 95 825 
Development of the Sporangia of the Phycomycetes .. .. 4 826 
Alternation of Generations in the Hypodermia.. .. .. 4, 827 
‘Mal Neroy2.0f, (hEAVANess voll eels ee ces 827 
PNAS (3 JOSH Op Whe WHC2 ep oe 827 


xx 


CONTENTS. 


Parasites of the Saprolegniee 

Diastatic Ferment of Bacteria 

Bacteria of Intermittent Fever - 

Bacterial Parasite of the Chinch Bug 

Etiology of Distemper .. 

Experimental Production of the Rico of Distemper 
Germs of Malaria se ss 
Prevention of Fermentation ie Venendile Acids 
Fermentation of Maize-starch joe ae 
Fermentation of Nitrates 


Lichenes. 
Nitro Of Tnchens) Yel tee yes) ee eee 
Thallus of Usnea articulata.. 
Structure and Development of the Mnoiieca of Sixchons 


Structure of Crustaceous Lichens we Oe. oS 
Canogonium and the Schwendenerian T, eter 
Life-history of Cora .. .. oe 


Minks’s Licheno-mycological Symi byl bias Feel 


Alge. 
Classification of Nostoc 
Diatoms of Thames Mud 
Symbiosis of Lower Animals with Plants 
“ Yellow @ells” of Radiolarians and Celenterates 
Cooke’s British Fresh-water Alge  .. 
Diatoms in thin Rock Sections 


Fineness of Striation as a Specific Giana of paint ae 


Schmidt's Atlas of the Diatomacee .. .. .. « 
“ Aphaneri”—Examination of Water  .. .. «x 
Crystalloids of Marine Alge 4p tad. Ae 
Phyllosiphon Arisari .. oc 

Structure of Corallina.. .. 


Impurities of Drinking Water Ser cf Veqouie Groth 


GSS USIPNONEE Mens ins Yes? as) oe ise 
Falkenberg’s Alge “2 
Motion of Diatoms a ee 


Note on Rev, G. £. Mills’ oie on Didone in | Ponwin 


Guano... 

Symbiosis of aie evih, Sane Cees ar 
Division of the Cell-nucleus in i. eee 
Batrachospermum.. .. «s «. Adee 
NAD PD EG IIACOG Mn ati ge) sales cs nat Ses 
Vampyreiarr me eeeam Met eee ee Pest hae as 
Schizophycee bis WE Ae Bo te, Mee 
Motion of Diatoms 


oe 


Disengagement of Oxygen a Vegeiabis Cells in sah Miero- 
-- Part 5 


spectrum oe we Ghaieae) vem 
Disengagement of Oxygen by Beeniiotarne 
Hydrurus besa i 


. Part 4 


CONTENTS. SOK 


PAGE 
Relationship of Palmeila to the Confervacee .. .. .. Part5 664 
Division of Closterium intermedium “.. 1 1+ 2 « 665 
Diatoms from the Island of Lewis... «+ oe we weg 665 
Composition of Fucus amylaceus.. .. =. =» « «+ Part6 834 
Mazea, a new genus of Cryptophyce@.. 1. +1 ewe 15 835 
Resting-spores of Conferva .. s» 6s 21 ws we wey 836 
SDS Of UO TRUO “So 09. 02 on, ON 837 
Motion of Diatoms. (Figs. 147-149) od EAE ene SOOT 838 
Symbiosis of Animals and Alge@ -.. 2. se se sew gg 839 
Vampyrelia andits Ales: 5 ee set es vs ar es 840 


MICROSCOPY.* 
a Instruments, Accessories, &c. 


White’s New Growing or Circulation Slide(Fig.1).. .. Part1 19 
Symons’ Hot or Cold Stage. (Fig.2)  .. Panes 21 
Goltzsch’s Binocular Microscope. (Figs. 3 and 4) 40° BOO 95 
Hartnack’s Demonstration Microscope. (Fig.5) +» «+ 5 97 
Lacaze-Duthiers’’ Microscope with Rotating Foot. (Fig. 6) % 97 
Nachet’s Portable Microscope. (Figs. 7-11) .. =. » 4 98 


Parkes’s “Drawing Room”? Microscope 12.» ss =» 45 100 
Piffard’s Skin Microscope. (Hig. 12) Shik pane ete ee 100 
Robin's Dissecting Microscope. (Fig. 13)... .. «2. «5 101 
Briiche Lens. (Figs. 14 and 15) Rit. UMS h Sob) o epOs ep 101 
The Model Stand... .. +» ? Sua ouiss 102 


Denomination of Bye - pieces oad Sendard Coc for same 103 
TAD Of HUCG OFT JANUS, co as) ooo 105 


Braham’s Microgoniometer ., .. + oo a8) gp 106 
Watson's Sliding-box Nose-piece (Figs. 16 Be 17) or oo. ey 106 
Deby’s Screw-Collar Adjustment, (Fig. 18) -. .. -» 5, 107 


Number of Lenses required in Achromatic Objectives So gp 107 
Lolour Corrections of Achromatic Objectives .. +» .. 45 109 
Verification ofp O0fECtuvGs) Wen will) 2a) a= eel erothh el) 55 109 
Schultze’s Tadpole-Slide. (Fig. 19) .. 1. +» «2 

. Stokes’s Tadpole-Slide. (Fig.20)  .. .. SAT eS eee 110 
** Swinging Substage” or “ Swinging Tuitpiece” 
Value of Swinging Tatl-pieces  .. 2. 21 «+ «2 
Ranvier’s Microscope-Lamp. (Fig. 21) Hols soon whol paces ey 112 
Hollow Glass Sphere as a Condenser .. By faa Mae 
Stein’s small Microphotographic Apparatus, (Fig. 22) ..  ,, 113 
Ranwier’s Myo-Spectroscope. (Fig. 23) .. .. -. «1 45 113 
ESOT OOK GP IUUBAROTAN) 09 90 0) dd oo oo oC 
Rogens, Micrometens. CHige 24)) a2) se es) | os ee eel ss 117 
Section of “* Histology and Microscopy” at the American 


Association 20 Paes cee go 00.) Go Ae 119 
Structure of Cotton Fibre aS Saale Ee. SY cee es ot a 119 
Presidents’Addnessy aay ane Ne een ne arta) 


so Acme 2 GlasseMicrascopca CLiga20) an conan es 251 


* Papers and notes abstracted in the Bibliography are also included here. 
b3 


Xxii 


CONTENTS. 
PAGE 
Brouning’s Portable Microscope. (Figs. 30 and 31) .. Part 2 252 
Harting’s Binocular Microscope. (Figs. 32 and 33) : + 253 
Nachet’s Double-bodied Microscope-tube. (Figs. 34 and 35) ,, 255 
Wenham’s Universal Inclining and Rotating rapes 

(Plate IV.) (Figs. 36-39) want... Sy eae 
Bausch and Lomb Optical Co?’s Tr hinosop, (Figs. 40 

and 41) ; <¢ 258 
“ Hampden” Postale Simple Mar oscope. (Figs. 42 Ee 43) as 258 
Excluding Extraneous Light from the Microscope . 260 
Nachet’s Improved Camera Lucida. (Figs. 44-46) .. a 260 
Abbe’s Camera Lucida. (Fig. 47) Peo ees £ 261 
Curtis’s Camera Lucida Drawing Arrangement .. 5 262 
Drawing on Gelatine with the Camera Lucida : “ 262 
Tris-Diaphragm for varying the ce a jective. 

(Figs. 48 aud\49) 9 ck ee oe : 7 262 
Gundlach $-inch Objective .. .. 25 my Oop 263 
Scratching the Front Lenses of FoR cgi naa 

UOT on OR. 0G | oe) oe 5 264 
Fluids for Renin eeae Immersion < 264 
Advantage of Homogeneous Immersion Dee cE 265 
Vertical Illuminator for examining ee Bpeierti, + 266 
Griffitl’s Parabolic Reflector ~ 266 
Forrest's Compressorium. (Fig.50)..  ..  . “ 266 
Julien’s Stage Heating Apparatus. (Figs. 51 ae 52) 5 266 
Beckh’s Achromatic Condenser for Dry and Immersion 

Objectives. (Figs. 53 and 54).. 5 270 
Pennock’s Oblique Diaphragm. (Fig. 55) . : 5 270 
Stereoscopic Vision with enedinenieaye Binocular A 

rangements, (Figs.56-58) .. .. a 74 271 
Dark-field Illumination by the Bull’s-eye Coudonton as 3 273 
Substitute for a Revolving table .. paue. Gs . 273 
Kitton’s Hollow Glass Sphere Illumination Tre US 
The Relation of Aperture and Power in the Moorunciee . Part 3 300 
GiApiLi SeLOrgule Microscope y saMiisieh altel gar aunicen nee) 135 395 
Parkes’ Class Microscope. (fig. 61) .. seta Ss 3 395 
Pringsheim’s Photo-chemical Microscope. (Fig. 62) . + 395 
Waechter’s (or Engell’s) Class or Demonstrating Microscope. 

(igs |CS:0nd GL)E 2k pe kan ncoh More anion ise 95 398 
Wasserlein’s Saccharometer Microscope. (Fig. 65) .. =: 399 
Wenham’s Universal Inclining and cial an FES Ae X55 400 
Briicke Lens.. .. 3 400 
Bausch and Lomb Bondy Diseactinay Mier oscope. (Fig. 66) 5 400 
Excelsior Pocket and Dissecting Microscope. (Fig. 67) . * 401 
Hartnack’s Drawing Apparatus ea s ibe 

(Gig 5G3) cae ne sSeoeeas 99 402 
Drawing from the Nata is Ga bearers hs) 404 
Ulmer’s Silk Thread Movement. (Figs. 69-72) 25), OB eer 406 
Diaphragms for Limiting the Apertures of Objectives. (Fig.73)  ,, 407 
Correction-adjustment for Homogeneous-immersion Objectives 407 
Hitchcock's Modified Form of Vertical Illuminator 9 409 


CONTENTS. 


Flesch’s Finder. (Figs. 74 and 75) .. 

Burnett’s Rotating Live-Bour 4. ..  .. 

Schklarewshi’s Hot-water Stage. (Fig. 76) 

Abbe’s Condenser. (Figs. 77 and 78) .. 

Bausch and Lomb’s Immersion Illuminator Bc 

Bausch’s Paraboloid .. .. cb hop 

Browning’s Simple Heliostat. (Fig. 79) . 

Hayem and Nachet’s Modified Hematometer. ee 80- $2) 

Fasoldt’s Test-plate Sth Ac 

High Resolving-power .. 

Binocular: Micnoscopesias= si esa scale ys eelee 

Electric Light in Microscopy 

Definition of Natural and Artificial 0b, Oe. 

Cole’s “ Studies in Microscopical Science”? . 

Journal of the Postal Microscopical Society 

Apparatus for obtaining Monochromatic Light .. 

Improvements in Seibert and Krafft’s Microscope 

Meaning of Sign x (Cf. also pp. 564, 746, and ae 

Apparatus for Drawing Objects .. ; 

Use of Diaphragms 

The Relation of Aperture Bil jeans in the Microwope 
(continued) - BGP com Vow 260) Wace 

Lossner’s ieeoneorore 350 BtheetiGo, He 

Prazmowski’s Micrometer Microscope. (Fig. 91) 

Simplified Reading Microscope for Horizontal and Vertical 
circles ae boa tl acieueoyer 

Swift’s Tank Microscope, (Fig. 92) . 

Teasdale’s Field Naturalist’s i Psxicza ie (479s. 93 ae 94) 

Steinheil’s Achromatic Eye-pieces. (Figs. 95 and 96) 

New Combination for Objectives... .. .. .. .. 

Fluid for Homogeneous Immersion 

Shurley’s Improved Slide for the eeninations of adits 
Matter. (Fig.97) .. .. AP eo Oct twicie oO uk BE 

Hardy's Coriano. (Fig. 98) 

Bulloch’s Diatom Stage we ae 

Substage Fine-adjustment. (Fig. 99). 

Sidle’s Centering Substage. (Fig. 100) 

Mounting for the “ Woodward” Prism. (Figs.101 ae 102) 

Prisms versus the Hemispherical Lens as Illuminators 

Radial Tail-pieces 

Electric Light in Drerescopne fr igs. 103 a 104). 

Black Backgrounds = 

Micrometrical Measurement iy means of Optical irae ac 

Malassex’s Improved Compte-globules. (Figs. 105-108) . 

Backgrounds, Light-modifiers, §c. Hol nel. ce 

Powell’s 3--inch Oil-immersion Objective 

Tadpole Slide : 

Impromptu Bramhall Reflector 

Bausch and Lomb een Co.’s * Profesional Meer aarane. 
(Fig. 1138) av, ae om Seen 40 


Xxill 
PAGE 

. Part3 409 
59 410 
48 
i 411 
a 412 
_ 412 
es 413 
“i 413 
43 415 
Fe 416 
55 416 
a 418 
7 420 
‘5 420 
oe 4OP 
- 422 
= 423 
“ 423 
5 424 
- 441 
. Part 4 460 
pe Bly: 
Pe 547 
s 548 
33 549 
m 549 
549 
a 551 
Po 551 
= 551 
5 5538 
“ 554 
55 554 
3 554 
554 
i 556 
% 557 
a3 557 
5 559 
xs 559 
- 559 
me 565 
a 565 
3 565 
3 567 
. Part 5 €66 


XxXiV 


CONTENTS. 


Bulloch?s Newer Congress Stand. (Figs. 114 and 115) 

Guillemare’s School Microscope. (Fig. 116) 

Gundlach’s College Microscope. (Fig. 117) 

Martens’ Ball-jointed Microscope. Sigh 118) .. 

Polarizing Microscopes .. 

Schieck’s Microscope with Vea ge Bnage Fi: 9. 119) . 

Projection-Microscopes. (Fig. 120) . 

Apparatus for Projecting an Image ts any ened Dis- 
tance with Variable Amplification .. . 

Waechter’s Travelling Dissecting Microscope. (Fig. 121). 

Measurement of the Power of Eye-pieces 

Hall’s Eye-protector for use with the Monocular Mirrontope 

Cramer’s Camera Lucida (also pita s and Oberhiuser’s). 
(Figs. 122-125) ae 

Bausch and Lomb Optical Cos Fine Aajsiment ge. 
126 and 127) 6 c Br 56 

Nose-piece for Binocular Petia AC : 

Homogeneous and Water-immersion Opccnmaee Ain” 

Collar-Correction of Objectives .. «. 5¢ 

Measuring Thickness of Cover-glass by Oorraciion Collar oe 

Bausch and Lomb Optical Co.’s Glass tak and Slide- 
carrier. (Fig. 128) .. Ani Ge 

Thomas’ Vivarium. (Fig. 129) a0 

Bausch and Lomb Optical Co.’s Tranorston Filiininater 
(Figs. 130 and 131).. : 

Gundlach’s Immersion Cp aap (Fig. 132) . at 

Symmetrical Illumination aol weavers 

Gundlach’s Substage Refractor : 

Silvered Convex Lenses v. Concave Mirrors 

Binocular Vision in the Microscope 

Miniatured Images. (Fig. 133) .. 

Black Annuli and Lines of Spherules and Threads 

Curiosities of Microscopical Literature 

Light Modifiers 

Schrauer’s Microscope .. aye 

Pelletan’s “ Microscope Continental 7 

Apparatus for Examining Fluids... 

Petrographical, Mineralogical, or Galaga peters 
—Rosenbusch, Fuess, Beck, Swift, §c. (Figs. kaa 

“ Jumbo” Microscope. (Fig. 156) BG 

“ Midget”? Microscope. (Fig. 156) . det hee ete 

Beck's Histological Dissecting Mirosop (Figs. 157 
ALAMOS) mecme ces ie Ns, aye Bo OB 

Gundlach’s Globe Lens 

Designation of Eye-pieces ..  «. 

Objectives of small and large Aper ‘ties 

Correction-adjustment for gman oneaiaranmeen Og aaine: 

Nelson’s Adapter for Rapidly Changing Objectives, (Fig.159) 

Gundlach’s Calotte Diaphragm. (Fig. 160) 

Bohm’s Wool-measurer. (Fig. 161) 


oe 


PAGE 

. Part 5 666 
es) 
(i) 
ere 
9 aba 
2) ee 
= 678 
5 a neme 
OTE 
» nG78 
a 16Te 
» 679 
» 683 
es 
» «685 
» mesa 
5» MERT 
5 eBy 
> NESS 
ess 
» 689 
» 658 
» 692 
» 692 
» 692 
» 693 
» 696 
> eS 
» 699 
» 00 
nes 
> a0 
Part 6 842 
5 aaa 
» 852 
eae 
ee 
»- sae 
ages 
» 854 
> es 
es 


» 859 


CONTENTS. XXV 


PAGE 
Gundlach’s Substage Refractor .. .. «.. « «  «» Part6 860 
Apparent Size of Magnified Objects .. .. «+ «+ « 4 861 
Committee on Ruled Plates .. bra COwavoha tach. doc 5 861 
Quekett Microscopical’ Club... 35 ts we owes Be 861 
Hogg on the Microscope po oO einai ad Hi soo abot ek Cach mime 862 
Wright's ‘ Experimental Optics’ Gab de Loo. (ANON eet ney; 862 
Moore’s Camera Lucida etna Gas RAMAN chek Cn erat) Be 95 865 
New Mechanical Lamp ae Aes Bp a ino wk itary 866 
Tolles’ Objective with Tapering Fr oo oo) yoo! tone dde =a 904 
B. Collecting, Mounting and Examining Objects, &c. 
Durable Preparations of me gee Organisms ., .. Part1 120 
Preparing Anthers .. a0.) gp 122 
Herpel’s Method of Pr ae Fungi for the eanan bo gf 122 
Dissociation of Gland-Elements ..  . Ob) G0. ep 123 
Method of Preparing and Mounting Soft Tissues Sutras 123 
Preservation of Anatomical Specimens 50) do boo gp A 
Barff’s Preservative for Organic Substances Srsdiea cine Rapa uh ber 124 
Injection-mass.. 860 OO SOB) a tae edo ©8400. Go Gs 125 
Imbedding Delicate Oasis 90 00.) 002 a0. 00 400.00 Fp 125 
Katsch’s Large Microtome. (Fig.25)  .. «1 se veg 126 
Cox’s “ Simple Section-cutter for Beginners” ..  ..  .. 5 126 
Cutting Sections of very Small ede FAV ootgeaobies Sabet aes 126 
Mounting in Balsam... .. Bic Nacesnerioam ahopal Ske An 126 
Mounting in Glycerine.. 12 «+ +6 66 es wwe 127 
Smith's Slides ati ABs Sob HOO ROE whoo becom rp 127 
Spring Clip Board. (Fig. 26) D0: 6D. Ob, $86»? 00.668 gp 128 
Examination of Living Cartilage +s 0 128 
Statoblasts of Lophopus crystallinus as a test hep High-power 
Objectives.—Areolations of Isthmia nervosa .. .. 5 129 
Microscopical Structure of Malleable Metals  .. »» »» 4 130 
Sections of Fossil Coniferous Woods .. .. oO 131 


Aeration of Laboratory Marine Aquaria. (Fig. 2)... cs, 131 
On Mounting Objects in Phosphorus and in a Solution of 

Biniodide of Mercury and Iodide of Potassium .. .. Part 2 163 
Injection of Invertebrate Animals Ag secant Coles Mllpeth “vole 5 274 
Goths IGYARHOG PUCES oo 00 00 00 50) 000 oF 275 
Staining with Saffranin AO. LE SOO ata ciOnyeO tna 0ati. Rede eeco 33 275 


Staming with Silver: Nitrate... 2. «6  « © «=» »% 99 275 
Staining Tissues treated with Osmic Acid .. .. +» «5 4 276 
Mounting the ‘‘ Saw” of the Tenthredinide  .. .. «. 276 
Mounting Butterfly-scales .. .. «ss oF «5 «2 oF 499 277 
Imbedding Ctenophora.. .. so O dal iinadh Vee 278 
Staining Living Protoplasm with Benearal: Ean a0. Dp 278 
Preservation of Infusoria and other Microscopical Organisms  ,, 279 
Staining the Nucleus of Infusoria Moc) areal San Seed creamer lt rey 280 
Aniline Dyes and Vegetable Tissues .. 11 «2 «+» « 145 281 
Indol as a reagent for Lignified WETS » Ane ete x 282 


English’s Method of ee ie and Wild 
LRMIGS. 5 odo i Hate Sy Boo 


XXVi CONTENTS. 


PAGE 
Mounting Salicine Crystals... «6 +e we we Swe «Part 2 283 
Bausch and Lomb Turntable. (Fig. 59) Foa ace 284 
GrapithiGell Vasu nie vost ood Mtawm Wee | (set Wee)! )) el Bee teas 284 


. 
. 

J 

. 


Bausch and Lomb Circle-cutter. (Fig. 60) ae) sie Lae MS 285 
Was and Guttapercha in we ae Ze eS Reet See ee 285 
PA Craton Uj PAGILATAG ecue Msctmees can esi etal ela) tote Ann tay 286 
TERRE CURES LEE “ag G0” So a0 “dow BOM LOB Bad ok oo 287 
Microscopic Curiosity .. sq cd) oe 288 
Colouring Living cnaae tend Depa: noe ot _ Pat 3 425 
Mounting Histological Preparations with Carbolic Acid ae ; 

Balsam... Stee ak Ode moc 35 425 
Differentiating Motor ae PET Ner DAT Oa ROW MIA co | of 425 
Preparing Nerve-fibrils of the Brain .. «2 01 ee ww 426 
Cochineal Carmine-solution .. .. he ome ap 426 
Polarized Light as an Addition to Sta aining 5b. oda oy 426 
Wickersheimer’s Preservative Liquid . se aes, See ass 427 
Preparing Hemoglobin Crystals bite om Wccvnestcle Wier anelies 427 
IPrrescroung eH VOWELS a itioh whe tse aisle iste OL tns ass 428 
Cleaning Diatoms.. .. eG ed od co 8 428 
Gaule’s Method of Tmbédding oe a 428 
Williams’ sage Micr otome adapted ae Use anitl ‘Ether, 

(G&G SED) on bo Sa 430 


Swift and Son’ s Fayraged Masaons: “Fe ie 84-87) od oF 432 
Bausch and Lomb’s Standard Self-Centering Turntable .. 434 


Crystallized Fruit Salt.. .. se we 5 ave keviegthee ol aiess 435 
Cleaning Gizzards ae Meas) cate Nasa kee Meck ato ane ete 435 
Mounting Starches si FO. rcp Oe rode 435 
Home-made Apparatus for Coliactond. dee fos pti aoe yoo ee cp 436 
Preparing Foraminifera... sot 436 
Mounting Volvox (Cf. also pp. 585, 586, aad 746) .. + eos 
Cleaning and Mounting Gizzards Seba Peels oles geen se “ako Osane 
Glycerine Jelly Mounts EE clon tgad) WsealMete agotheghars Ges Meecoienes 
Examining Rough Minerals... .. Ah og | ob. Oo as 437 
Keeping Objects Alive for many Months es 5 438 
Examining Circulation of Blood in a Tudo’ Tail (Ch 

AIO MD OOG) aa. ees 5 as | ES 438 
Transparent Injections of a veal Manna | WS Ae oD 438 
Preparing Entomostraca .. ‘ as 439 
Simple Plan of Imbedding Tissues oe one Cutting in 

Semi-pulped Unglazed Printing Paper .. .. «. « Part 4 474 


Cutting and Mounting Microscopical Sections .. « « 4 567 
Preparing Blastoderm of the Chick .. ss «+ «+ «+ 5 570 
Preparing Embryos of Insects .. «. Seyi bel calin bec aes 570 
Collecting, Staining, and Photographing Rude apes | as 571 
Ehrlich’s Method of Exhibiting the Bacteria of Tuberculosis 572 
Preserving Infusoria and Amebe cial yA. ates Haas omaeee Ce Tas 574 


Preserving Protozoa .. .. oe; ase PG MSCS. “cs 575 
Staining the Nucleus of Living Tabane se hie Oy cae as 576 
Double Staining with Carmine and Anilin Green nay some Sey 576 


Outing Sections of "Coal, in y.0 see fess) eel igs 577 


CONTENTS. 


Sections of Mica-schist .. 

Paper Cells .. 6 00. 66-1 90") 60 han 
Was, Cells... as bude of We cince used Wiicls 
Miller’s Caoutchouc Canes 90 00. 00.60 
Mounting in Phosphorus 90 6 
Vacuum-bubbles in Canada oan 00 ad 
Mounting Moist Objects in Balsam 

Moisture in Dry Mounts 

Dammar Varnish . bb Bacio HG 
Cleaning Used Slides and Case 

Resolution of Amphipleura ipalncida ae 
Microscopic Examination of Wheat-flour 


Destruction of Microscopical Organisms in Potable Water 


Public Lectures in Microscopy 50 
Preparing Stellate Hairs of Deutzia .. 
Examination of Leaves 


XXVll 


Preservative Fluids for Animal ae Weqenile iiss, and 


Methods of Preservation .. 
Preparing Sections of Aais-cylinder 
Mounting Gizzards of Insects 
Preparing Tape-worms 
Staining and Preserving Tube- ante 
Method for Dry Preparations 
Preserving Infusoria 60; / 00 
Mounting Mosses and Hepatice .. 
Preparing Bacteria of Tuberculosis 
Preparing Diatoms a0 
Modification of Paraffin- Anteniog 50 
Perenyi’s Hardening Fluid . 


oP) 
Satterthwaite and Hunt's Freezing Sechioncutien| (Fig. 138 5 710 


Windler’s Microtome. (Figs. 135 and 186)... 
Marsh's Section Knife. (Figs. 137 and 138) 
Thanhoffer’s Irrigation Knife. (Hig. 139) 


Differential Staining of Nucleated Blood-corpuscles .. 


Flemming’s Modified Method for Staining Nuclei 
Lodine-green for Human and Animal Tissues 
Teichmann’s Injection-mass .. 

Wywodzen’s Injecting Material .. 

Mounting in Pure Balsam .. 

Centering Objects on the Slide .. 

Chalk Cells 

Line and Pattern oun . 

Kain’s and Sidle’s Mechanical Bangers’ a 140) . 
Venice Turpentine as a Cement .. 20. 06 
Metal Caps for Glycerine Mounts 


Nassau Adjustable Spiral Spring Clip. (Fig. Taye 


Green Light for Microscopical Observations 
Photo-Micrography 


PAGE 

ee athaeonc 
5 578 

35 578 

9 579 

i 579 

ee ess 581 
ae 582 
os 583 

Sal os 583 
ee aes 583 
saenigs 584 
. 584 

3 585 

. 585 

BAe de 587 
fences 590 
Part 5 701 
a 703 

as 704 

5 704 

5 705 

5 705 

ny 706 

a 706 

on 706 

op 707 

» 708 
709 

5 711 

a5 712 

35 713 

55 714 

5 715 

on 716 

3 716 

po wiley 

se ee 
LT 

o 718 

S 718 

os 721 

= 724 

[ 725 

oS 725 

po 12D 

A 726 


Woodward’s Photographs of Aniplipteara aa Dieu: junnna 5 727 


Microscopical Examination of Handwriting 


a, te 


XXVill CONTENTS. 


PAGE 
Haamination Of-Sputa se 2, 25 cs we ws so, ATO 
Trichina-Examinations Ac uber Sock. oh 728 
Continuous Observations of Minute anienacil Fee acl teensy 731 
Microscopical Examination of Textile Fabrics ..  .. «+ 5 732 
The Microscope in Engineering Work... .. «2 «ss «oF 733 
The Microscope in Metallurgy .. ee toe, <p 735 
Micro-Chemical Methods for Mineral Aa tiste cal 1 eetU Mee, alles 736 
Microscopical Characters of Hailstones .. x 741 


Appearances presented by Air-bubbles and Fat glues in 
White and Monochromatic Light. (Figs. 142-145) .. 4, 742 


“ Patent Knotting” as a Cement 57619 rie UE Olas  has ses 745 
LBP WCCO aot) Oth Oe Cie GO Mot wach oo 3 746 
Gita PEMLLOMMOSETAGA a tea. a wae lias) er-icit! rete ners gs 746 
Mounting Molluscan Palates Bevo as ft hee “tiie © since Mt Males 746 
Cabinet for Slides .. .. Rend cat © Lee Sie 747 
Mounting Plant-hairs and aig. aise” ia ET oN ames 748 
Killing and Preserving Insects ... «. SC ct ieee 748 
Further Improvement in the Groves- Williams Ether eae 

Wicrotome. (Fig. 146) .. .. os ye * LartiGaioo 


Methods of Microscopical (rea m use in the Zoological 

Station at Naples. (Fig. 162) ik wae © eet \eslad Ode ee 866 
Andres’ Methods of treating Actiniew .. .. 11 + «8 4 881 
Flemming’s further Method for Staining Nuclei a0 SS cp 883 


Todine-qreen and Methyl-green .. «a «s «ce 0s oe 55 883 
Preparation of Hpidermts’ ... 1. 25 s+ se 00 ‘as 955 883 
Unpressed Mounting tte.) Mee Mes) ice!) ye’) soe Wise ace 884 
Staining with Magdala-red .. «1 ss cay ce SSS 885 
Preparing Fossil Foraminifera, et fe sre Ape ctoe ae Maes 887 
Preparation of Diatoms Ss OM at Ae cp 887 
Mounting Sections in Series... x 888 
Eau de Javelle for Removing the Soft Pas of Preparation > 889 
Gum and Glycerine for Imbedding .. .. = 890 


Roy’s Microtome. (Figs. 163 and 164) .. «1 «2 +» 1459 892 
Boecker’s Microtome with Automatic Knife-Carrier. (Figs. 

165-167) .. .. Pape eee! Mie ne eres Bes Se 893 
Staining Bacillus Fascias emits Were, (eke enna Wl Mas Ald 895 
Substitute for Canada Balsam .. 15 20 6 oF «2 9 898 
Cnn GISeCONe MGIPES, “"L.0y st) ss ues) ee) | Wer) eens 899 
Staining Fat-cells ee ae toe ie ees 899 
Taking up Small Objects by Suction Tubes SAD Lob. 2p 900 


BIBLIOGRAPHY—MIcROSCOPY a Be ietsh ise ecole 4 io yqtaee inate’ Sia eae ne 


” - - on oe oe “- oe oa ” 


; 
° 
mR 
Q 
‘S) 
Lae] 
Ls} 
D 
Qn WH Raho 
bo 
[o'e) 
<j 


CONTENTS. 


OBITUARY 


PROCEEDINGS. OF THE SOCIETY— 
December 14, 1881. 6 
December 7, 1881 (Genperar ino} 
January 11, 1882 De 
February 8, 1882 (Annual ice 

Treasurer’s Account for 1881 : 

Report of the Council es to the Asner Meeting 
MiarchySsplSS 2 sem accmess a02" os! v0. sdb nseos = ae 
April 12, 1882.. BHO, hee ag enncosatae 
April 26, 1882 (Conversazione) . 

May 10, 1882 . OC 
June 14, 1882 . 6 
Revert of @onmittes on Standard Gamers es Bye- wien 
and Substages Go nee at tool tee o tag a tad eG lee 
October 11, 1882 
November 8, 1882 . 


INDEX BRAM see ait ateteh aya seee eee ey eluate mela Boh) aero ete eee 


Part 6 


XX1X 


PAGE 


899 


133 
137 
140 
289 
292 
293 
294 
439 
444 
445 
989 
595 
901 
909 


913 


The J ournal is issued on the second Wednesday of 
February, April, June, August, October, and December. 


To Non-Fellows, Zh 


» Ser. II. : 
Price 4s. 


id Be Path. FEBRUARY, 1882. | 


JOURNAL 


a = REVAL. 
_ MICROSCOPICAL SOCIETY: 


CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, 


AND. A SUMMARY OF CURRENT RESEARCHES RELATING TO 


(principally Invertebrata and Cryptogamia), 
MICROSCOPY, Sec- 


Ldited by 


FRANK CRISP, LL.B., B.A., 
One of the Secretaries of the Society 
OS ae and a Vice-President and Treasurer of the Linnean Society of London ; 


WITH THE ‘ASSISTANCE OF THE PUBLICATION COMMITTEE AND 


A, W. BENNETT, M.A., BSc., ~ F, JEFFREY BELL, M.A,, 
ee _ Lecturer on Botany at St. ahonae s Hospital, Professor of Comparative Anatomy in King's College, 


8. 0. RIDLEY, M.A., of the British Museum, asp JOHN MAYALL, Jun., 
FELLOWS OF THE SOCIETY. 


WILLIAMS & NORGATE, : 


A 
~LONDON AND EDINB H, ue] 


} eran BY WM. CLOWES AND SONS, LIMITED,] ae [STAMFORD STREET AND CHARING CROSS, 


JOUR. u 


ROYAL MICROSCOE,.. 1L SOCIETY. 


Ser. 2.—VoOu. Ih. PART ‘1: 
(FEBRUARY, 1882.) 


CONTENTS. 


—_—07g{00-—— 
TRANSACTIONS OF THE SooreTy— ; PAGE 
I.—Fvrruer Nores on Barris Orreatipz. By A. D. Michael, F.LS., 
F.R.M.S. (Plates I. and II.) ., .. 1 
II.—A New Growine or Crecuration SLIDE. By AM (hareaee White, 
M.R.C.S., F.RMLS. (Fig.1) .... ss 19 
TH 208 a Hor on Cony Biden vo anu Micuocoor, By W. HL. oie 
Symons, F.R.MS., F.C.S. (Fig. 2) phage os 21 


Summary OF CuRRENT RESEARCHES RELATING TO Tose’ AND 
Botany (PRINCIPALLY INVERTEBRATA AND CryprocaAmta), Micro- 
scopy, &¢., INCLUDING OriGgINAL CoMMUNICATIONS FROM FELLows — 
AND OTHERS 2. SF 8 ee ee Rn a ee ee 


ZOoLoey. ae 


Photographs of the Developmental Process in Birds . 
Development of the Paired Fins of Elasmobranchs 
Development of the Sturgeon... fi 
Development of Petromyzon Planeri .. pep 
White Corpuscles of the Blood .. 
Nerve-endings of Tactile Corpuscles .. .. % 
Distribution and Termination of Nerves in the Cornea ae Seay ti be es 
Influence of Food on Sex _.. Sal oe MRSS Ae TSS. SONU ay ee ee 
Digestion of Amyloids in Cephalopoda Be igen cos Dees eeomeee 
Proneomenia sluiteri 
Development of Salpa .. AAS cin SoC gua ea pare See 
Tunicata of the * Challenger’ =i ete 
Striated Muscle of Coleoptera and its “Ner ve-endings = 
Terminations of the Motor Nerves in the Striated Muscles ck Insects 2 
Wings of Insects... Bs a 
Structure of the Proboscis of Lepidoptera 
Post-embryonic Development of Diplety Se te a ee 
Development of Adoxus vitis va Piao uae eee tae eee 
Colouring. Matter from the Willowtree Aphis Sat Cees ae eS 
Liver of Spiders .. i. peels pre: tees Bauer ame 
Limulus an Arachnid .. .. 
Function of the Catdal Spine We fe oe CIES hen) oa Steg RCN 
Adaptations of Limbs in Atyoida SL bce We VETER Sp RKO eh ae 
Colour-sense in Crustacea .. 4. Re See at ep ey pee 


Germs of Artemia salina _.. So alae s ei 
Origin of the Central Nervous System of the Annelida i ee ee 


Swim-bladder-like Organs in Annelids  .. orks Ea Sg 
Development of Polygordius and Saccocirrue .. Se ase Oe 
Termination of Nerves in the Voluntary Muscles of the BP e 

The Echiurida .. gdp suis ipo ee Oe 
Segmental Organs and Genital Gland of some Sipunculida Para se Sk 
Anatomy and, saps of a nudus Saar 1 3% Dye Satin ot eee 


3) 


Summary or Current Resean 3s, &c.—continued. 


PAGE 
Sternaspis .. z Eraea poe ‘sited oa ing fee) wee ware Beh hess, eee SO 
‘Hamingia glacialis Z ee EL Seid RE SR Ni Pan Se tN Re ea | 
Fichinorhynchus 11 «> Sap nice Nag lsen Tete aa a en Co sea ea eh ee ADE 
Proscolex of Bilharzia b= BUDE gia use ap etna IF bel ok ne Gait Seo SE 
Nervous System of Ces# y eit SIE DE eae are Rats a tie eR eC | 


Development of the Ovu* of Melicerta aie eh ate Tk a pier plat cower an i eae eee DO 
Development of the Skeleton ul the Eee Be re pak salt notte oalhes sea wa Poe 
Asterias < er BB wise O's hth HESS Sosa ae OO 
Spines of Asteroidea .. Wee Peerage tear een Sette ak TOT 
Prodrome of the Anthozoan Fauna of Naples Sea) any Ban gee ty ROW ese ay / 
Metamorphoses of Cassiopeia borbonica .. > 1 ss news ta eS 
Development of Geryonopsida and rane Rega igi ea, ate aise og Cea eS 


Se 3 Fission of Phialidium variabile See rate RED he oe Res ede tage 
eee ~  Crambessa tagi .. halt hep CpeR I eee Coats be eet Pee th cays net DO 
Sexual Cells of Hydroida UP Ne fet S RY aS ti Sea on Re YE Cia ogee | 
Spermatozoa of Hydrozoa :. —. Sep REL Ava oie ate ee ps Geet ee OO 
Attempt to Apply Shorthand to Begnaes BaD eee Be SU ae es eee OL 
Flagellata.. Leelee tes cng eee : 62 


_ Infusoria Parasitic in Cephalopods RES ha es Bey = 63 
Parastes:0f the chide <6 casos.) fae 8 he ees aka RE eas = ve Fe OB 


Botany. 
=Drigin of the Embryo- sac and Functions of the Aupelal pel ve . 64 
Polyembryony in Mimosez . = ob | hen BS or OD 
- Resistance of Seeds to extreme Cold .. sro ae VO0 


Mechanical Contrivances for the Dispersion of Seeds and “Pritts partes te OG 
Chemical Difference between dead and living Protoplasm hee 
Energy of Growth of the Apical Cell and-of the youngest Seginents detiiee OU 
Action of Nitrous Oxide on Vegetable Cells a ee 
Chlorophyll and the Cell-Nucleus Sige eer earns Oe 
Influence of Warmth of the Soil on the Cell. formation g. Plants 
- Growth of Starch-graimns by Intussusception esse 
Collenchyma _ nc Sa serrierteo reed | t 
_. Epidermis of the Pitchers of Sarracenia and Darlingtonia eigen Vole enue ke 
acres perous Vessels” ee Oxs eae G2 oe he SF ins ain) Cag eB a ee TD 
Epidermal System of Roots Slee Glad boa May oGeadal Sues, oa its ak UO 
f Passage from-the Root tathe Stem 3.0 ve ee ce ne ee ae oe A 
Causes of Eccentric Growth eR an wees Sead ge TE lod OR SGU FL 
Hydrotropism of Roots : SC emICN See Oe GR RG Fone es ee 
- Cause of the Swelling of Root-fibres STO i eer Nee VERE T Sgn Ge pa omer {5% 
Frank’s Diseases of Plants... .. 1, ss Bolg ar dames See ag ee a 
Prothalliwm and Embryo of Azolla ..... APPR GONE SES EY [1 


Development of the Sporangia a at Spares o Tsoctes: tn vee cae EB 
- New Genera of Mosses .. .. x obras ges tan yaa ge 
Classification of Sphagnacez Sera Penne Pe ae ETE PR EE a AS 


 Cell-nucleus in Chara fectida — 26-00 0e ce se a ee ee ee 9 
__ Conidial Apparatus in Hydnum 1. eee ae ne ce eee 80 
- Alternation of Generations in Uredinee .. 1. +s ae as ws aw ee 80 
Mode of Parasitism of Puceinia Malwacearim fa Bh Goad AiG) hs Meera sae SOO 


- Sterigmatocystis ... Seas 2 ‘ os ae pa SO 
Oospores of Phytophthora infestans Pe ao : F . i ee Ok 
pane ~ Peronospora viticola GaAs Hp ees Paka OR 4 - - Sl 
- .. Vegetation of Fungi in Oil . " eee, 3. § 
ores PAT OSTA PRUIGE 6.2 0 We Seal Sih By iad idem. Gist bey hae ea Se eee ee 
_ Ear-Fungi... wad Heiss pains Rios LI ew oh Ue OR EL. aie ee ES 
~ —Insect-destroying Chieienate Sere a iret Seer rer eee By SR REE OES ae 30. 
 Brefeld’s Schimmelpilze — .. Spee ee Peete ie Se pene ep ISD 
~ Influence of Light on the Growth of Penicillium pape nee eS : 87 
Production of Microphytes within the Figg eee NE Ee > 87 
: Atiology of Diphtheria —.. WEES Ear : x SBF 
Properties and Functions of Bacteria. Se eng hong eerie <t. 
_ Atmospheric Bacteria .. SPR ae Or ae ae Pa eae 
- Pathogenous Bacillus in Drinking ‘Water Pcs aks Panes 6 elias Pan El eps 2.” ole 
Connection of . Diseaste with Les Bacilli Ae oe Aen re prea a ea 
: ra 


Cs) 


Summary or Current ResEarcues, &c.—continued. 


PAGE 
Origin of the Lowest Organisms — ee ae 
Prolongation of Vegetative Activity of Chlorophyltian Cells. ‘sanidet the 
Influence of a Parasite... 93.2%: 
Classification of-NOdDC o> S92 ve 2h ga ae oe 8g oe aw? ees oa EO 
Diatoms Of -Thannee: Mak i635 5 OS ge ae. ae te eee 


Microscopy. 


Goltzsch’s Binocular Microscope (Figs. 3 and 4) 4. © we we es 
Hartnack’s Demonstration Microscope (Fig. 5) .. 85 Foe 
Lacaze-Duthiers’ Microscope with Rotating Foot (Big. | 6) 

Nachet’s Portable Microscope (Figs..7-11) — .. 

Parkes’s ‘‘ Drawing Room” Microscope .. 

Piffurd’s Skin Microscope (Fig. 12) Ree Sime aco tit 7 
Robin’s Dissecting Microscope (Fig. 1) ss Bae Abts si Semple 
Briicke Lens (Figs. 14 and 15) Bes aA Ga Ope an eek 

The Model Stand - 

. Denomination of Ey ye-pieces ‘and Standard Gauges Jor same 
Braham’'s Microgoniometer : Bese oe 
Watson’s Sliding-box Nose-piece ( Figs, 16 and 17) 

Deby's Serew-Collar Adjustment (Fig. UT) Se apes 

Number of Lenses required in Achromatic Objectives 

Colour Corrections of Achromatic Objectives .. 

Verification of Objectives .. Orang ea 

Schultze’s Tadpole-Slide (Fig. 19) 

Stokes’s Tadpole-Slide (Fig. 20) .. 

* Swinging Substage’ » or & Swinging uil-pizee” 

Value of Swinging Tail-pieces*... ..- . 

Ranvier’s Microscope-Lamp (Fig. 21) Br rey pea oo 
Hollow Glass Sphere as a Condenser... o voee tae aaies 
Stein’s small Microphotographic ee Cig 22) Fe tae 
Ranvier's Myo-Spectroscope (Fig. 23)... PEERS 
Standard for Micrometry .: -+ ee ae te te ene we 
Rogers’ Micrometers (Fig. 24) . ‘ fs 
Section of “ Histology and Microscopy ” at the ‘American Association : 
Structure of Cotton Fibre .. - . 5 ea oo eee 
Durable Preparations of Microscopical Organisms Aen eter oD 
Preparing Anthers _.. ns eet eee 
Herpel’s Method of Preparing Fungi for the Herbarium deat ge Re 
Dissociation of Gland-Blements if . = be SSP ee wine 
Method of Preparing and Mounting Soft “Tissues. 
Preservation of Anatomical Specimens .. 6s tenet nee 
Barf’s Preservative for Omani Substaysces <5 eat so sass > Gs eae 


Injection-mass.. SFE IRL OR MS ek FE Part SY Coe 
Imbedding Delicate Organs Bo Stree: crap ee earl nee More ie 
 Katsch’s Large Microtome (Fig. 95) Reema. SAE a cup tt pa ap ten 
Cox's “* Simple Section-cutter for Beginners” Biscay: Ses Pay ae 
Cutting Sections of very Small PG suri oe Se rf 
Mounting in Balsam... ED eRe te ee, si 
Mounting in Glycerine sre See keari vies: suerte eee = 
Smith’s Slides — -«. Twat de ee” Me ans taal ene eign 
. Spring Clip Board (Fig. 26) - pele Wis hater Ppllgics < Seu Are GF: 


Examination of Living Cartilage ia 
Statoblasts of Lophopus erystallinus.as a Test for High-power Objection 5 aS 
Areolations of Isthmia nervosa... +... ys 
Microscopical Structure of Malleable Metals bien) SI aee es 
Sections of Fossil Coniferous Woods aa Pet ae et 
Aeration of Laboratory Maring Aquaria (Fig. 2 spauh asi enant 


PROCEEDINGS OF THE Soorrry ae wa age c ade Sage Pot i 


— Bopal Microscopical Society. 


MEBTINGS FOR 1882, 


At 8 PM, 


1882. Wednesday, JANDARY ee’ Ore Ot ee AT 


Be FEBRUARY... p23 


(Annual Meeting for Election of 0. ficers 
and Council.) 


Wane: BL gf ois te AES ae eee 8 
S PEP RIT eos ae ae ee BAND 


ME Anh Se EE ey eas ea tey eee RO 
e SPUN sce a ae oe re ee 
Se OcTOBER Eee Sie oy ake te ey eek 
5 - Novemser ais ee se aia ae a 8 
is DECEMBER ey es eee) TS 


THE “ SOCIETY? STANDARD SCREW. 


The Council have made arrangements for a further oe of Gauges 
. and Screw-tools for the “Socrery” SranDaRD Screw for OBJECTIVES. 


‘The price of the set (consisting of Gauge and pair of Screw-tools) is 
: ‘12s. 6d. (post free 12s. 10d.). ee for sets should be made to the — 
_ Assistant-Secretary. © 

For an explanation of the intended use of the gauge, see Journal of the 
SS Batty, L. ae pp. 548-9. 


_ ADVERTISEMENTS FOR THE JOURNAL. 


a “Mr. Cuartes Buencows, of 75; Chancery Lane, W.C., is the authorized 
Agent and Collector for Advertising Accounts on behalf of the Society. 


(oS) 


NOMINATIONS FOR THE COUNCIL. 


8th FEBRUARY, 1882. 


Proposed as PRESIDENT. 
Pror. P. Martin Duncan, M.B., F-.B.S. 


As VICE-PRESIDENTS. 


_ Pror. F. M. Batrovr, M.A., F.RS. 

*Ropert Brarrawaire, Esq., M.D., M.R.CS., F.LS. 
*Ropert Hupson, Esq., F.RS., F.LS. 

JoHN Ware SrepHenson, Hsq., F'.R.A.S. 


As TREASURER. 
Lionet §, Bears, Esq., M.B., F.R.CP., FBS. 


As SECRETARIES. 


CHarues Stewart, Esq., M.B.CS., F.LS. 
Frank Crisp, Esq., LLB. B.A., V.P.LS. 


As Twelve other MEMBERS of COUNCIL. 


*Lupwie Dreryrus, Esq. 
Cuartes James Fox, Esq. 
James GuaisHer, Esq., F.RS., F.RAS. 
*J. Witu1am Groves, Esq. 
"A. pe Souza GuimaraEns, Esq. 
Joun KE, Inepen, Esq. 
Jonn Mayatn, Esq., Jun. se ees 
Arsert D, Micuarn, Esq., F.LS. » a on Ce hee os 
 *Joun Mizar, Esq., LRCP.Edn, FLS. = 
 @Wrwam Tuomas Surrors, Esq. Se ag 
“Freverick H. Warp, Esq., M.R.C.S, . 
T. Cuarrers Wurrs, Esq., MRCS, F-LS. 


* Have not held during the preceding year the oflice for which they are nominated. e 


(7:2) 


I. Numerical Aperture Table. 


The “ AprrtuRE” of an optical instrument indicates its greater or less capacity for receiving rays from the object and 

transmitting them: to the image, and the aperture of a Microscope objective is therefore determined by the ratio 

- etween its focal length and the diameter of the emergent pencil at the plane of its emergence—that is, the utilized 
diameter of a single-lens objective or.of the back lens of acompound objective. 

This ratio is expressed for all media and in/all cases by n sin uw, nm being the refractive index of the medium and wu the 

-semi-angle of aperture, ‘The value of 7 sin w for any particular case is the “‘numerical aperture ” of the objective, 


Diameters of the ~ Angle of Aperture (= 2 w). Theoretical 


3 * 2 : Pene- 
Back Lenses of various * | INumi- Resolving a 
____ Dry and Immersion Wamorseat D Water- | Homogeneous-| nating Power, in paLe 
~~ Objectives of the same Py Da pees OD} ee Immersion\. Immersion | Power. | Lines to an Inch.| ~?Y*"- 
- Power (4 in.) ¢ = yechiveS: | Objectives,| Objectives. | (a2) | (A=0°5269 1 e ) 
from 0°50 to 1°52 N. A. @=1) | =1:33.)) (m = 1°52.) =line 2.) a 
180° 0! |2°310| 146,528 “658 
161° 23’ | 2°250 144,600 *667 
153° 39’ | 2-190 142,672 *676 
147° 42’ | 2-182 140,744 "685 


142° 40/ 
Fo Aa ee ie 

wa), 1842 10! 

fo ee 13002 2! 

126° 57’ 

is 123° 40 
180° -0'|. 122° 6! 
165° 56’| 120° 33 
155° 38"| 117° 34’ 
148° 28’| 114° 44 
142° 39’| 111° 59’ 
137° 36"| 109° 20° | 
133° 4"| 106° 45! 
128° 55} 104° 15! 
125° 3"| 101° 50! 
121° 26"| 99° 29’ 
|118° 00'| -97° 11’ 
114° 44"| 94° 56’ 
111° 36"| 92° 43’ 
108° 36’} 90° 33’ 
105° 42"| 8° 26’ 
102° 53’| 86° 21’ 


-074| 138,816 | +694 
‘016. 136,888 | -704 
-960| 134,960 | -714 
“904| 133,032 | °725 
-850| 181,104 | +735 
-796| 129,176 | *746 
Hq. 128,212 >|. 752 
-742| 127,248 | +758 
-690| 125,320 | -769 
-6388| 123,392. | -781 
121,464 | +794 
“588| 119,536 | -806 
‘488| 117,608 | °820 
-440| 115,680 | +833 
-392| 118,752 | +847 
-346| 111,824 | -862 
-300| 109,896 | +877 
-254| 107,968 | -893 
210} 106,040 | +909 
-166| 104,112 | -926 
-124| 102,184 | +943 
082} 100,256 | -962 
100° 10’| 84° 18’ |1-040| 98,328 | -980 

0’ | 97° 81"| 82°17" | 1-000} 96,400 

9/1 94°. 56"). 80° 17’ | 960) 94,472 
99 | 99° 94’| 78° 20"| +922) 92,544 

6’ | 89° 56’| 76° 24’) -884| 90,616 
51! | 87° 32'| 74° 30’| °846| 88,688 
19’ | 85° 10’| 72° 36"| -810| 86,760 
17’ | 82°.51'| 70° 44 | -774| 84,832 
38’ | 80° 84'| 8° 54’ | -740| . 82,904 
17’ | 78° 20'| 67°°.6' | -706} 80,976 
10’ | 76°. 8’| : 65° 18' | -672| » 79,048 
16’ | 73° 58’) 63° 31’ | -640| 77,120 
81! | -719.49'| 61°. 45' | -608} 75,192 

56’ | 69° 42"|. 60° 0’ | -578| 73,264 
28' | 67° 36'| 58° 16' | +548; 71,336 
6". | 65° 32/| 56°32’ | +518) 69,408 

Bl’ | 68° 31’| 54° 50’ | +490} 67,480 
41’ | 61°-30'| 53° 9' | +462| 65,552 
36' | 59° 30°}. 51° 28’ | +436 63,624 
35 | 57° B1’|° 49° 48’ | -410| 61,696 
38’ | 55° 34’| 48° 9" | +384] © 59,768 
44’ | 53°-38'| 46° 30' | -360|- 57,840 
5a’ | 51° 49"| 44° 51" | -336|-" 55,912 

6 | 49° 48") 48° 14" | +314) 58,984 
22''| 479 54!) 41° 87'.| +292) 52,056 
40" | 46° 2/) 40° 0’ | -270) 50,128 
0’ | 44°.10'| 38° 24’ | +250) . 48,200 


a ee ae re ee al ol old ole le we) 
or 
Go 
oo 


eR Re ee 
(Jt) 
i 
lor) 


Nore 
ow 
ot 
oo 


- Exampre.i—The apertures of four objectives, two, of which are. dry, one water-immersion, and one oil-immersion, 
s ~ qwould be compared on the angulan aperture view as follows ;—106° (air), 167° (air), 142° (water), 130° (oil). 

So Their actual apertures are, however, a8 >< sae - *80. “98 1:26 > 1°38 — or their 
_ aumerical apertures. : 


Pic Meo 
de ee: 


{enw 


(8) 


II. Conversion of British and Metric Measures. 


, $3, 


(1.) Linea. 4 
Seale showing Micromiilimetres, §c., into Inches, §c. Inches, §¢., into mt 
ane race ies M ins. mm, ins. | mm, ins, ue MO el * 
hee 46 Titchibes 1 “000039 i “039370 5 2-007892 | ins, % 
| “000079 ‘078741 2-047262 |> 3. 1-015991. 
ee 3 000118; 8 ‘118111| 58 2°086633 | 5°2°° a 
qe ane 4 +000157) 4. -157482| 54 2°126003 | —23°° 7.699318" 
5 +000197| 5 196852 | 55 2°165374 | 17" 9+53997 
aA 6 -000236) 6 -236223 | 56 2°204744 |. 22°" 9-899107 | 
Ee 7 -000276| 7 “975593 | 57 2°244115 | 2°" 3.474979" 
=n 8 000315) 8 314963 | 58 2+283485 | 2°? 3. gogRag: 
E | 9 -000354|; 9 “354334 | 59 2322855 |. 722° g.agg9q% 
Bie a 10 -000394| 10 lem.) -393704| 60 (6cm.) 2°362226] 24" 5.079954 
Ale -| 11 -000433"| 11 433075 | 61 2401596 | ides 67349943 
AG 12 -000472| 12 "472445 | 62 2440967 | sooo _ 8° 4660915 
| 13 -000512| 18 “511816 | 68 2°480337 | ano 12°6998867 
les 14 -000551| 14 551186 | 64 2°519708 | tooo 25°399772" 
=& A715 +000591 | 15 °690556 | 65 _ -2:559078 
[es 16 -000630| 16 “629997 | 66 2-598449 | 
=a 17 000669 | 17 “669297 | 67 2°637819 
lz | 18 -000709| 18 -708668 | 68 2°677189 
oH 19 -000748 | 19 748038 | 69 2°716560 
IE z| 20 :000787| 20 cm.) -787409| 70 (7 cm.) 2°755930 
= 
[Ee 21 -000827| 21 26779 | ‘71 2°795301 
| 22 -000866| 22 *866150| '72 2° 834671 
Es 23 -000906| 23 -905520 | 73 2- 874042 
| 24 -000945| 24 “944890 | 74 2913412 
es 25. -000984 | 25 “984261 | ‘75 2° 952782 
HE 26 -001024 | 26 1:023631| ‘76 2992153 
= 27 -001063 | 27 1:063002 | 77 3031523 ; 
le 28 -001102) 28 1:102372| '78 *-3°070894 | 23° 
= 29 +001142; 29 1°141743 | '79 8-110264 s. 
E 30. -001181 | 80 (3cm.) 17181113} 80 (Som.) 3+149635 | 3° 
E B1 --001220} 31 1:220483| 81 3°189005| ve 
2 82 -001260| 82 17259854 | 82 3+228375 | as 
lz 33 *001299 | 33 1:299224| 83 3:267746 | az 
= 84 :001339:| 84 1°338595 | 84 3°307116 | zo 
lz 35 :001378| 35 1°377965 | 85 3-346487| = 
= 86 -001417| 36 1-417336 | 86 3°385857 | a 
rE 37 -001457| 37 1456706 | 87 3*425228 | ae * 
= 88. 001496} 38 1496076} 88 3°464598 | > ¥ 
E 89 001535 |. 39 1:535447 | 89 3503968 = 
E 40 -001575| 40 (4om.)1-574817) 90 (9 cm.) 3-543339 | a5 
= 41 -001614| 41 1°614188 |} 91 “.3*582709 . 
(E 42 001654 | 42 1°653558| 92 3-622080 | 2. 
= 48 -:001693| 48 1692929 | 93 ~ 8-6614501 4° 
1B 44 -001732| 44 1°732299 | 94 3°700820 | 2. 
Is E 45 -001772} 45 1:771669 | 95 3-740191 |. gs 
= 46 -:001811)} 46 — 1°811040'} 96 3°779561 | ae 
} E “47 .:001850| 47 1850410] 97 8818932] 
= 48 -:001890; 48 1°889781| 98 - 4 3*858302 J. ota: 
te 49 +001929| 49 1:929151, 99. ©" B:80767B Fg 
= 50 ‘001969 | 50(5 cm.) 1-968522 | 100 (10 om.=1 decim.)| 2: 
r [ 60 002362 peti * SS Re 
lE 70. °002756. decim. ins, f Been 
iis 80 003150 aed 3°937043. bet 
lz 90 +003543 2 7874086 — ANS. 
= 100 = * 003937 3 11°811130 ete? 
IE 200 -007874| a -15°748173 sek) 
= 300 -011811 5 19° 685216 epee 
[ 400 | :015748 6 ‘23°622259 poe 
a 500 | :019685 7 Q7°559302 ore 
1} 600. +023622 8 31°496346 te 
10004 =1 mm. || 700 *027559 9 35483389 oe 


10 mm.=1 em. 800 :031496; 10 (1 metre) 39°370432 hu 
=1dm. | 900 :035433 | | (= 8:280869 ft, . 
=1metre.||1000(=1mm.) |) 0-2 1098623 yds 


- 


ecchch ete 
£6GE SCP. os 
aeces. ‘a1 D 0002 BS ; 
C6FES + *ZO ¢.LSP “ILOAT “Sq] § 
Paes m bemne See OOL. Som P8GEES-F = CIPS 1) $LG- LL] ‘ST[°3 160066- = 
eae ELEGSe- “10 k : 
Som = Pe qoae 0 ie Z99889-T OOL | > -sqund $zL092-1 = 
C6RGLE-9 OL es (13.1) of res ape ‘J “quo eTgego. = 
906TESS 6 FII6S8- 8 : Te : orgt Or 
OTOEST.¢ 8 GLECFS GL 8 POOLEL-T OL | peo mL D ony 
LE6SES -F be FP9GOS- OL By as is OEE ne 
LEGLES«S 9 60F6SS-6 9 FLOIES: 6 : Lae Sa Sk a 
seer ; ara} : épa¥e0-9 ae OFS  GEEG19- 98 009 
eae é en ee ee og |.  ge9ste-08 _ 008 
6968F6+T g L629 - OB saat 308. : a 
6LE6G63-T i 0LF980«8 G GCELLG-G Ng | pn age ca abe 
eee pega ae -souutasinep ay) Sova 167.4 LLOGOS- GL 006 
s00Te8.¢ . 48 eee 8 6Eec0L-9 CTP 1) OOF 
—~ 001g8-¢ 6: ; j Groloep 1) OUT sce O&60TS-T & ale ea 
916881-S 8: LI6S888-T 06 POOLPL-T Res HORE TSS a8 
o Lec? ap SSFeG-E 08 Se tee Seal LLITLG AS Ghee) 
LE6L88-¢ 9. £9G080-1 FN a DL SA NOTES 56 2 Ruse ccriore SURES RODIN Leer, ae 
— 8F6684:S ¢. 1F6G26- 09 ess eo a ee eee 
 SS6168-3 F: <HIOULLA SOG 3 aay Lee a OO Ee Te a 
6968F6-T g- FOGLIO- Mi OF Sates : e Se ees re anda gee 
6L666-1 2G: OLEZOF- 0g GGeLLs- ee Pe : nee 
RiysPejangaauenes) aiecys) LEONE - t 0G ~ G99889-T -. ity ae Sealy (ytyT80 D OL Cate o 
CO86LF-9 I: SStSL- (-15T}U90 T) OL -  96LFLF-T ee Gate aoe 4 
9U6TES-S 60: | Tegser- 10 OOO Ss ey OZ88F- o8: 
9T6S8T+G > - 80- 6SFSEL- ee ey alt he SER os 
LZ6SES-F LO. 96080T- nen aon Sree he eee Ske: : 
LE6LE8.8. oe O80. F6S260- 9 PLOTES 6 ae: Oe eee a Reo 
St668S-E cO. Z9TLLO- —g _ TIgs6l-8 Sus ae Rae coe: 
SE616S-Z Lo BO. We GELTIO. 82x eels  6F9FGE-9 as enc to 
696EF6-T mn e0e te LEZOFO- g :  E86516-7 tee Sadopate aie 
cae ene Aa i as qoseeact. ore code Sep eSOOMOO! «5 Fe a 
Se a it a ce 3 Bate Me “sotumersiy || SOUT UE ‘sur, rejoins al Pas $SOp'qno > ee > ROUTE 


ae ‘souaunabogi Onur “0.6 ‘suipap Op ‘sump oyun “08 Snag: °f ‘oom ie “98 err ong. 


“aura mn & g) 


2p ‘Ssoyoug ongng: “opin ro ‘Sogn 3 


(10) Eee 


III. Corresponding Degrees in the 
Fahrenheit and Centigrade 


Scales. 


See : 
YMNOHWeOorR 
oo 
ive} 


iw) 
od . . . - 
HOG PNOLANWHAAPD ONAIWH DD 
eS seb OO 02 CO SIH bo ARWwWroOon 


PER ett apt 


oo 
onaOownl 


~ #06 


SWORN OK 


PoANWaAHKS 


DNOSRODNWHHOANHDHOAWHHSANW 


~ 104°0 


or 43) to 70° 3 
Phosphorus See hs 65°. 47 
Bisulphide ef carbon apa, Sam 
Flint glass ~ : 5° 30! to 58° 8 9 
Crown glass — 56° ou 40. ie 
Rock salt 5 
Canada balsam 


- Pure water 
(Airs 


IV. Refractive Indices, Dispersive © 
Powers, and Polarizing © 
Angles. Se 
(1.) Rerractive INDICES. - 


= € Mean values.) — i 


Diamond 2-44 to 2° 735 S 
Phosphorus ages 7 224 © 
Bisulphide of carbon Soret 678 


1-576 to 1" 642 
1°531 to 1° 563” bY 


Flint glass 

Crown glass 

Rock salt 

Canada balsam 

Linseed oil (sp. gr. * 982) 

Oil of turpentine (sp. gr. +885) 
Alcohol 1-372 
Sea water pean 1-343 
Pure water Ls "336 
Air (at 0° C. 760 mm.) A: Bsa Si 


WwW 


(2.) DisPERSIVE POWERS. 


Diamond 

Phosphorus 

Bisulphide of carbon 

Flint glass 

Crown glass 

Rock salt 

Canada balsam 

Linseed oil (sp. gr. *932) pes 

Oil of turpentine (sp. gr. Ss: +048 

Alcohol 10 29. 

Sea water Bane fc 

Pure water : ees ifs 

Air Es ae 
G3.) POLARIZING ANGLES. 


Diamond 


Linseed oil (sp. Bt. 982), SF 
Oil of turpentine (sp. gr. oe Sepak 
Alcohol eer 

Sea water 


vs 


( ll) 


V. Table of Magnifying Powers. 


id ed petit vs ee, and 7. more than the figures given in this column. 


oe Pee and Lealand’s No, 2—= 7°4, and Beck’s No. 2 and Ross’s B = 8 magnifying power, or 


SEES. EYE-PIECES. 
Beck’s 2, 
Beck’s 1, | Powell’s 2, Beck’s 4, Beck’s 5 
Powell’s 1, and Powell’s3,| Ross’s C, | Beck’s 3. Powell’s 4,1 Ross’ a E Powell’s 5.§ Ross’s F. 
Ross’s A, | Ross’s B, Ross’s D. 
nearly.* 
be é Foca Lreneru, 
Sate: [o} 
a3 E gia. | tim, | Lin | tin 2 |: | ie lj 
a2 A 3 in, 5 6 3 in x in To 12 3 in. ~ in. 
: 2 E ’ MAGNIFYING POWER. 
8 be 
ee lg | 7, | 10 | 121 | 15 | 20 | 25 | 30 | 40 
si! on AMPLIFICATION OF OBJECTIVES AND EYE-PIECES 
co oes COMBINED. 
bo 2 10 15 20 25 30 40 50 60 80 
4 24 123 182 25 314 374 50 623 75 100 
3 82 ~ 162 25 332 412 50 662 835 100 1334 
2 5 25 37k 50 624 75 100 125 150 200 
4% |. 62 331 50. 662 83 | 100 1331 | 1662 | 200 2662 
14. 10 50 75 100 125 150 200 250 300 400 
8}. 123 623 932 feet oe 1562 | - 1873 250 3122 375 500 
2 134 662 100 1331 | » 1662 200 2662 3334 400 5334 
75 1124 150 1874 225 300 375 450 600 
100 150 200 250 300 400 500 600 800 
125 1872 250 3124 375 500 625 750 1000 
e150 225 - 800 375 450 600 750 900 1200 
1662 250 3831 4162 500 6662 8332 | 1000 13332 
200 300 400 500 600 800 1000 1200 1600 
250 375 900 625 750 1000 1250 1500 2000 
300 450 600 — 750 900 1200 1500 1800 2400 
850 525 700 875 1050 1400 1750 2100 2800 
400° 600 800 1000 1200 1600 2000 2400 3200 
450 675 900 1125 1350 1800 2250 2700 3600 
500°. 750. 1000 1250 1500 2000 2500 3000 4000 
550 825 1100 1375 1650 2200 2750 3300 4400 
600 900 }- 1200 | 1500 1800 2400 3000 3600 4800 
650 975 1300 1625 1950 2600 3250 3900> 5200 
700 1050 1400 1750 2100 2800 3500 4200 5600 
750 1125 1500 1875 2250 8000 3750 4500 6000 
800. | 1200 1600- 2000 2400 3200 4000 4800 6400 
850 1275 1700 2125 2550. 3400 4250 5100 6800 
.- 900 1350 1800 2250 2700 3600 4500 5400 7200 
950 1425 1900 |. 2375- 2850 83800 | . 4750 5700 7600 
1000 4 1500 2000 2500 8000 4000 5000 6000 8000 
1250 1875 2500 8125 3750 5000 | 6250 7500 § 10000 
O lf 1500 2250. | 3000 3750. | 4500 4 6000 7500 9000 | 12000 
2000 3000 4000 5000 6000 8000: 4 10000 | 12000 } 16000 
Oj} 2500 3750 5000 | 6250 7500 §¥ 10000 | 12500 | 15000 | 20000 
| 3000 4500 6000 7500 | 9000 4.12000 {| 15000 | 18000 | 24000 
4000 6000 8000 | 10000 | 12000 16000 4 20000 | 24000 } 32000 


( 12) 


HENRY CROUCH'S 


LAD, First-Class Microscopes. 


Student’s Microscope. 


New Family and School 
Microscope. 


Wew Series of Objectives. 


New Accessories. 


NEW ILLUSTRATED CATALOGUE, ON RECEIPT OF STAMP, MAILED ABROAD FREE. 


HENRY CROUCH, 66, Barbican, London, B.C, 


AGENTS IN AMERICA, é 


“JAMES W. QUEEN & CO., 924, Chestnut Street, Philadelphia, U8. 


JOURN. R.MICR. SOC. SER. II. VOL. IL PL.1 


haat 


West Newman & C? bith 


A.D. Michael ad not. del. 


8 1—5. 
6-9 


ocellatus 


Scutovertex maculatu 
Cepheus 


JOURN. R. MICR. SOC. SER. I. VOL. I. PL.I. 


West, Newmar £ C° lith 


6. 


ipes 1-5. 


otaspis lacustris 
- 


a: 


Dameeus monil 


N 


JOURNAL 


OF THE 


ROYAL MICROSCOPICAL SOCIETY. 


FEBRUARY 1882. 


TRANSACTIONS OF THE SOCIETY. 


eet 


1—Further Notes on British Oribatide. 
By A. D. Micwazt, F.L.S., F.R.M.S. 
(Read 14th December, 1881.) 
Puates IL. anp IL 


Since my last communication to this Society, I have continued my 
observations upon the life-histories, and general habits of the 
native species of Oribatidz, and also my collection of these minute 


EXPLANATION OF PLATES I. ann IL 


Pate I. 


Hie. 1—Scutovertex maculatus, adult. x 100. 

>, 2-—The same, nymph. 

»  9o—The same, adult; a, stigma; 6, stigmatic organ. x 370. 

»  4.—The same, adult; a, portion of maxillary lip; 6, palpus. x 3760. 

»  o.—The same, adult; mandible. x 370. 

s  6.—Cepheus ocellatus, adult. x 80. 

5», %—The same, nymph, nearly full grown; showing larval and two 
nymphal cast notogastral skins, the bordering scales of the 
existing skin not haying yet passed far beyond those of the 
former skin. 

5 8.—The same, adult; a, stigma; 6, stigmatic organ; c, wing of the 
tectum ; d, terminal spine of same; e, hair set in at commencement 
of spine; f, portion of the tectum. x 170. 

»  9.—The same, adult; the mandible. x 370 (reversed). 


Puate IL. 


Hic. 1.—Dameus monilipes, adult. x 160. 
» 2,—The same, nymph, full grown; showing the larval and two nymphal 
cast notogastral skins. 
5, ¥3.—The same, adult; a, stigma; 6, stigmatic organ. x 350. 
»  4,—The same, adult; a, portion of maxillary lip; 6, palpus, with 5th 
joint reflexed. x 450. 
» 9. —The same, adult, Ist leg; a, coxa; 6, trochanter (so called); c, femur 
(so called); d, enlarged tibia ; e, tactile hair on same; f, tarsus; 
g, monodactyle claw. 
»  6.—WNotaspis lacustris, adult. x 105. 
5,  %.—WNotaspis licnophorus, adult. x 180. 
4, 8.—The same, adult; a, stigma; }, stigmatic organ, x 570. 
Ser. 2,—Vok. II. B 


2 Transactions of the Society. 


creatures, with a view to making our fauna more generally known. ~ 


It is the experience of every one entering upon an almost untrodden 
path in natural history, or indeed in any other science, that at first 
new species and new facts accumulate rapidly and easily, while, 
after a time, novelties, whether of observation or of species, are more 
difficult to find and more laborious to follow out. I am not an ex- 
ception to this rule, and naturally I cannot record the number of 
additions which I was able to make in my former papers. My 
searches have, however, been rewarded by finding species which I 
believe to be not only new to Britain, but entirely unrecorded any- 
where, and which are far too numerous to be figured in the neces- 
sarily and properly limited number of plates which the kindness of 
this Society can place at my disposal. I do not think that written 
descriptions of creatures of this nature are of much real service 
without drawings, as, after all, words are but a vague way of 
identifying form upon which so much depends. I also think that 
drawings, to be of use to other naturalists, must be upon a sufficient 
scale to show detail, particularly with such organisms as the 
Oribatidx, where specific distinctions depend greatly upon the for- 
mation of the essential parts of the cephalothorax, which in itself 
is frequently very small in proportion to the abdominal region. I 
have therefore thought it best, in this paper, to describe and figure 
a few of the more interesting unrecorded species with, I hope, some 
degree of exactitude, rather than to figure a larger number upon a 
scale which might possibly not be sufficient for identification 
hereafter. 

Before proceeding to notice the unrecorded species, I will deal 
with such further observations as I can place before you relative to 
the habits, &c., of this family of Acarina. 


Deposition or Protection of the Ova. 


Tt will be found, by those who read works referring to this sub- 
ject, that a great number of naturalists broadly state that the 
Oribatide are viviparous. I am not quite sure where the idea 
originated ; some suppose that Claparéde is responsible for it, but I 
fail to find anything in the writings of that excellent observer 
which in any way justifies the accusation. His only work treating 
of any of the Oribatede, as far as I am aware, is his chapter on the 
development of Hoplophora contractilis (as he calls it), in his 
‘Studien an Acariden,’ and in this he expressly says that the idea is 
erroneous. It is not of much importance where the suggestion 
came from, but it is more worthy of remark that it has found its 
way into the works of some of the ablest and most accurate writers, 
who of course did not take it, or profess to take it, from their own 
observations, but simply on the authority of others; thus, for 


Further Notes on British Oribatide. By A. D. Michael. 3 


instance, Huxley,* talking of the Acarina, says: “Most are 
oviparous, but the Oribatide are viviparous.” This statement, in 
spite of the high authority for it, is certainly an error, although 
there may be a few exceptional instances of it, as will be seen later 
on in this paper, but those instances are, as far as I am aware, 
recorded here for the first time. The impression which has got 
abroad among naturalists, and held its ground so tenaciously, is, 
perhaps, the more curious, because Nicolet, the principal author who 
has written upon the Orcbatidz, says that the egg is deposited, and 
that the larva emerges very shortly afterwards, and this dictum of 
the French acarologist, in my opinion, correctly states what really 
occurs in a great many, and probably in the large majority of 
instances, 

The result of my own observations has been to convince me that 
the matter is not quite so simple as naturalists have supposed, and 
that it is not possible to lay down one general rule which will be 
correct in all cases; indeed, this remark is applicable to most ques- 
tions connected with Acarina. I have usually found that if I have 
attempted to generalize from a few known instances the rule which 
I thought I had found has broken down, and I have also found that 
a great number of the general laws enunciated by other observers 
fail to stand the test of a wider experience. 

It seems to me that there are at least three if not four modes by 
which the eggs are brought to maturity, and the larve hatched, in 
different species, or under different circumstances. 

The first method is that so well known in insects, that the egg 
is deposited in a fertilized but only slightly developed state. The long 
ovipositor, or extensile oviduct, of the female Acarid is used for this 
purpose, and the egg is placed in crevices of the wood, moss, or 
fungus, upon which the larva will feed ; the egg adheres, either by a 
certain viscid quality in its exterior envelope, or more often is 
attached by a few threads of silk-like substance. Segmentation may 
have gone on in the egg to some extent before deposition, but very 
little progress has been made towards the differentiation of any in- 
dividual parts of the future larva. A very considerable time often 
elapses between the deposition of the egg and the hatching of the 
larva in this mode, and I think that the creature probably often 
passes the winter in the egg state, and is only hatched on the 
approach of spring. I have frequently had the eggs myself for a 
long time before hatching in various species, as, for instance, 
Dameus geniculatus, D. clavipes, Nothrus theleproctus, &e. 

The second mode is that which Nicolet apparently considered to 
be universal, and which I myself believe to be the most frequent, 
particularly in full summer. ‘This is, that the development of the 


* A Manual of the Anatomy of Invertebrated Animals.’ London, 1877, 
p- 383. 
B 2 


- Transactions of the Society. 


egg is almost completed within the body of the living mother, and 
that the egg is extruded, certainly as an egg, as in the first method, 
but with the larva so fully developed that it escapes from the ovum 
very shortly after deposition. 

I have a strong suspicion that a third mode, only to be found 
in exceptional instances, is that which Huxley states to be charac- 
teristic of the family, viz. that the female is viviparous or ovo- 
viviparous. This, if it occur at all, is probably not the case at all 
seasons of the year, even in the species where it may take place 
during the period of most rapid reproduction. I have not any 
proof or certainty that this mode ever exists, for I have not ever 
witnessed the birth of a living larva, unenveloped in any egg-shell, 
from any of the Oribatide, but I have dissected out of the body of 
a female, either living, or killed immediately before, a larva, which, 
although not sufficiently strong or active to run, has been fully de- 
veloped, and able to kick its legs and move its trophi in a very 
vigorous manner, and exhibit other signs of life. In addition to 
this, I have several times found larve in a cell where I had kept a 
pair of adults, and which I had carefully examined for ova a short 
time before without detecting any. I do not place much reliance 
upon this last reason, as the ova are sometimes extremely difficult 
to find in consequence of their smallness, their want of colour, and 
the places in which they are laid; but, as far as it goes, it is in 
favour of the occasional viviparous theory. 

In the above-named three methods only one, or at the utmost 
two eggs are matured at one time; the reason for this 1s evident 
enough, as the egg is so large as to appear disproportionate to the 
size of the body, and many could not be ripe at once consistently 
with the life of the Acarid. 

I believe that the fourth method has not hitherto been 
recorded by any observer, and it appears to me interesting, I 
have noticed it chiefly in the case of Oribata globula, but it pro- 
bably exists in other species. It is as follows: The female, 
instead of maturing only one or two eggs at the same time, 
matures a much larger number, often a dozen or more, so that the 
abdomen appears to be entirely filled with them; these eggs are 
not laid, neither do they hatch within the body of the living 
mother, but the mother dies with the abdomen distended by fully 
formed eggs, in which the larve have not been developed. The 
whole contents of the abdomen except the eggs seem to dry up 
and disappear, leaving the chitinous shell of the parent as a pro- 
tection to the ova. This condition of matters often lasts for a 
considerable time, indeed I believe that Oribata globula often, or 
usually, passes the winter in this state. When the larvee are at 
length hatched, they escape by the opening of the camerostomum, 
the labium having probably dropped off, or by the genital or anal 


Further Notes on British Oribatide. By A. D. Michael. 5 


opening, the folding doors which close these respective apertures 
having also dropped off. Sometimes the apertures are so small, or 
the larvee so large, that they cannot easily escape by the apertures, 
-and I have more than once had to assist those I had bred in 
confinement by breaking away the shell. 

Dr. G. Haller, of Bern,* lately recorded the finding of 
numerous dried exo-skeletons of Hoplophora in winter among 
the fallen leaves, each shell having a large single mature egg in it. 
Haller concludes that the female Hoplophora, when about to 
deposit an egg, seeks for the exo-skeleton of some deceased member 
of its own species, and uses it as a shelter for the ege. It is of 
course quite possible that this may be so—I cannot deny it—but, as 
Haller does not appear to have seen the egg laid, and he was 
hardly likely to have done so, as the Oribatedz object to light, I 
cannot help thinking that this is probably another instance of the 
fourth method above described, with the distinction that here only one 
egg is matured at once. If it be not so, it is odd that the Hoplo- 
phora should always choose the exo-skeleton of a Hoplophora 
instead of distributing its favours more generally amongst other 
genera. 


Deutovum Stage. 


Another observation which I have to record, is relative to the 
development of the egg after extrusion. The eggs of some 
Oribatide are of a rather leathery consistency, those of other 
Species are provided with a hard chitinous shell, which is brittle 
‘and non-elastic. Claparéde, in his ‘Studien an Acariden,’ records 
the occurrence, in the ova of Ata bonziz, of what he calls a 
deutovum stage; Megnin has observed a similar thing in the case 
of Trombidium fuliginosum, and I myself noticed it in the ova of 
other Trombiduidz, but I am not aware of any one having observed 
it amongst the Oribatide. I have now to record that it decidedly 
is equally a portion of the life-history of some, but not of all, 
members of this family. The deutovum stage is as follows: 
When the exterior shell of the egg is hard and non-extensile, the 
gradual increase of volume in the egg-contents produces so much 
pressure from within upon the shell that the latter splits sharply 
all round its periphery, dividing it into two somewhat boat-shaped 
halves; the inner membrane which lines the shell has in the 
meantime increased in strength, and has become the true en- 
velope. The space between the two broken halves of the exterior 
shell is at first a mere line, but, as the contents increase, this line 
widens, and the halves of the old shell get pushed further and 
further apart, showing a broad white space (the inner membrane) 


* “Miscellanea acarinologica,” MT, d. Schweiz. entom, Gesellschaft, 1879, 
No. 4, p. 502, 


6 Transactions of the Society. 


between them. It is along this line that the rupture takes place 
when the larva escapes, as recorded in my first paper on the 
Oribatide in this Journal.* 


Wood-boring Species. 


Claparéde, in his ‘Studien an Acariden,’ records the result of 
his excellent observations on Hoplophora in its immature stages, 
his discovery that the larvae and nymphs were wood-boring 
creatures, and he expresses his astonishment at finding that the 
nymphs and larvze were soft white creatures, when the adults are 
so hard and dark; he calls it passing through an Acarus stage. I 
find that Hoplophora is not by any means an exceptional instance 
in either of these particulars. The nymphs of Hermannia arrecta, 
Tegeocranus elongatus, Cepheus vulgaris, and some others, live in 
dead wood, which they perforate with long burrows in all direc- 
tions, until the wood is often thoroughly riddled by them, only the 
thinnest partition being left between the burrows. The larva or 
nymph, as the case may be, is usually found at the end of the burrow 
furthest from the mouth, being in fact the last place which it has 
worked to; the burrow behind it is usually filled with excremental 
matters and wood-dust. The nymph of Tegeocranus coriaceus 
burrows into the more solid fungi in exactly the same manner, 
and there are doubtless other boring species which I have not yet 
traced. It is rather interesting to observe that, in all of these 
instances, the larvee, or nymphs, are soft, white creatures, entirely 
without the defensive armour or other protection possessed by 
members of the family which are more exposed to danger than 
these sub-cortical species. 


Eedyses of Leiosoma palmicinetum. 


Those who have seen the beautiful nymph of Leiosoma 
palmicinetum, which is figured in a former paper of mine in this 
Journal,t will not readily forget it. I was curious to see how the 
very large Japanese-fan-shaped, membraneous hairs, which form 
a broad border round the abdomen of the nymph of this species, 
were disposed of during the formation or ecdysis. I had naturally 
imagined that they would be folded up, either by closing the 
nervures together like a fan, or else transversely like the wings, &c., 
of insects. The extremely simple and pretty method by which 
nature effects the packing did not strike me. The elegant mem- 
braneous hairs grow on the edge of the body, and are formed fully 
expanded ; instead of being doubled up, their peduncles are simply 
turned down a little, so that the palmate hairs lie flat against the 
ventral surface of the Acarid, and are thus protected from injury ; 


* Vol, IL. (1879) p. 225. + Vol. IIE. (1880) Pl. III. 


—— 


Further Notes on British Oribatide. By A. D. Michael. 7 


the two pairs of immensely long setiform hairs, which spring from 
the edge of the abdomen, are also bent down upon the ventral 
surface, instead of being folded, and there form a diagonal cross. 
The whole arrangement may be most distinctly seen through the 
existing skin, pending one of what, for want of a better name, I 
call the inter-nymphal ecdysis, i.e. a change of skin which does not 
take place upon any transformation, but simply upon the nymph 
growing larger. I have luckily succeeded in mounting a specimen 
in this condition which shows the whole arrangement admirably. 
I have not figured it from want of space. 


New Species. 


Among the unrecorded species described and figured below are 
one or two which may be worthy of some remark, although I have 
not any very striking novelty to record this time. 

In my paper published in the third volume of this Journal, 
page 186, at the end of the description of the nymph of Leiosoma 
palnucinctum, I stated that I had brought home what I had 
supposed to be several very young specimens of that nymph found 
upon the golden lichens growing upon the rocks of the Land’s 
End, but that, when examined with a higher power, they turned 
out to be a different species, the shape being slightly longer, and 
the nervures of the palmate hairs irregularly furcate instead of 
reticulated. I also stated that they had not attained the adult 
condition, and that I doubted their surviving the winter; that 
doubt became considerably stronger as the winter advanced, for my 
captives became to all appearance dead, and I feared that the only 
thing to be done with them was to mount them as specimens. I 
was still unwilling to abandon a hope, however remote, of tracing 
the species, and my patience was in this case rewarded, for, as the 
spring advanced, the apparently dead nymphs began to move about 
very slowly, and finally underwent their last transformation, and 
there emerged an adult, which was new to me, and I believe 
unrecorded, and which was moreover quite distinct from anything 
I had seen, and was a handsome species. The interesting part 
was, however, that, although the two nymphs resembled each 
other so closely that it required a careful examination with a 
moderately high power to find out the difference, and although 
they were utterly different from all other known nymphs, and 
notwithstanding that they came from the same place and both fed 
upon lichen, yet the imagos were quite dissimilar, and not in any 
way to be included even in the same genus. Palmicinctum is a 
Leiosoma, and the present species, although it does not fit very 
well into either of Nicolet’s genera, yet is certainly a Cepheus, 
unless a new genus were made for it, which does not seem to me to 


8 Transactions of the Society. 


be desirable. I have called it ocellatus from the curious effect, like 
two great eyes, produced by the globular stigmatic organs (or 
protecting hairs as Nicolet calls them) being sunk exactly in the 
mouths of the stigmata. This is the only instance of such an 
arrangement which I am aware of in the Oribatidz. 

Another somewhat singular creature is the very minute being 
which I propose to call Notaspis lienophorus: here again the 
peculiarity is in the stigmatic organs, which are flattened, and so 
large as to appear quite disproportioned to the Acarid. When I 
have had this tiny creature alive on the stage of the Microscope 
for the purpose of observing or drawing it, I have seen the 
stigmatic organs blown about by the wind. 

A third very curious new species is the one I propose to call 
Damzus monilipes: the remarkable part of this creature is the 
form of the legs, particularly the first pair, where the tibia is a 
globular mass which appears altogether too large for the Arachnid, 
and gives it the effect of carrying a mace on each side. 

A fourth curious species I propose to call Notaspis lacustris : 
the peculiarity is its being strictly aquatic, and being often found 
covered with diatoms. 

In conclusion I may briefly allude to certain slides which have 
been in circulation of late as being mounts of an Acarus supposed 
to feed upon the Phylloxera; those that I have seen have been a 
collection of various Acarina, of different families—in fact anything 
and everthing found upon a vine; amongst them were more than 
one of the Oribatide. I think that such information should be 
received with extreme caution, as I am not aware of any well- 
authenticated instance of any species, which really belongs to this 
family, being habitually predatory. 


Descriptions of Species. 


CEPHEUS OCELLATUS n. sp. Pl. I. Figs. 6-9. 
Average length about *6 mm. 


“3 breadth ,, ‘32 mm. 
8 length of legs Ist, 2nd, and 3rd pairs about *24 mm, 
” ” 9 4th pair about *32 mm. 


This species does not fit very happily into any of Nicolet’s genera, 
but I do not think it is desirable, at present, to create a new genus 
for it. The only one of the existing genera in which it can be 
included is Cepheus, and in that genus I accordingly place it 
provisionally. 

It is a somewhat singular, and very well marked species. The 
colour is very dark brown, often almost black, and the texture is 
dull, without the slightest gloss. 

The cephalothorax is rather more than a third of the total 


Further Notes on British Oribatide. By A. D. Michael. 9 


length, broad, and flat. The rostrum blunt, the tectum large and 
well marked, its wings (or lamella) very large, nearly on edge, and 
projecting far beyond the anterior edge of the horizontal surface of 
the tectum; at their anterior termination these lamelle are trun- 
cated and slightly rounded, from the lower angle of the truncated 
edge springs a stout spine, which curves forward and downward, 
and almost touches the tip of the rostrum. A little above this 
spine, on the same truncated edge, is a much thinner but rather 
longer spine, or hair, almost parallel to the thicker one. Hach 
lamella increases in width as it nears the abdomen, and terminates 
suddenly, with a rounded shoulder, just in front of the stigma. 
The stigmata are placed at the junction of the cephalothorax and 
abdomen, they are very large and open: the opening faces straight 
upward. The stigmatic organs (or hairs) are globular, and are 
gunk in the mouth of the stigmata, which gives each stigma the 
appearance of being an enormous eye—it is from this effect that I 
have named the species. This peculiarity alone would be sufficient 
to distinguish the present species at a glance from every other 
which I am ‘acquainted with. The interstigmatic hairs are short 
spines just inside the stigmata. The palpi are subcylindrical, 
with the first joint much the longest, the third and fourth very 
short, the fifth conical and densely haired, labium longer than 
broad, mandibles very small. 

The legs are stout, all joints except the tarsi very rough and 
irregular in outline, the second joints much the thickest, the tarsi 
short and stout. The first two pairs reach considerably beyond 
the rostrum, the fourth pair only slightly beyond the posterior 
margin. ‘The tarsi are clothed with numerous very thick hairs, 
the other joints have very few hairs on them. 

The abdomen is oval, truncated anteriorly, with the antero- 
lateral angle produced so as to form short points projecting 
forward and almost touching the stigmata. There is a broad 
flattened margin, somewhat raised towards the edge, all round 
the abdomen, except where it joins the cephalothorax; this band 
bears a row of blunt spines, not quite regularly arranged ; inside 
the band the notogaster is arched, but not very strongly; it is 
divided by ridges into irregular strips or bands, of which one or 
two run nearly parallel to the anterior margin and the rest run 
more or less longitudinally. There are usually about ten bands in 
the width ; each band contains two rows of round pits, the position 
of the pits being alternate, i.e. the pits in one row come between, 
and not opposite to, the pits im the adjoming row. The anal 
plates are very large, and the genital plates are close to them; 
both sets are sub-oblong in form. 


10 Transactions of the Society. 


The Nymph. 


This is so similar to the nymph of Leiosoma palmicinctum * that 
I think it will be convenient to poimt out the differences rather 
than to describe the whole creature again. The present species is 
a rather longer and narrower elliptical form than palmicinctum. 
The beautiful expanded membraneous hairs, each shaped like a 
Japanese fan, which form a broad border all round the creature in 
both species, are similarly arranged along the lateral and posterior 
margins of the abdomen in both species, but in palmicinctum they 
also run round the anterior margin, entirely covering up the 
cephalothorax. In the present species they are absent from the 
anterior margin of the abdomen, but they complete the elliptical 
border of hairs by running round the margin of the cephalothorax 
itself, and a similar hair on each leg of the first pair completes the 
border below the rostrum. This hair is absent in the nymph of 
palmicinctum, but is present in the larva of that species. The 
result of this arrangement is that the cast notogastral skins borne 
on the back of the nymph have not any expanded hairs along 
their anterior margins, paliicinctum has. ‘There are three pairs of 
similar hairs, but longer and more pointed in form, down the 
centre of the notogaster, being in fact upon the notogastral 
portion of the cast larval skin. Another very leading distinction 
between the two species is that in palmicinctum the nervures of the 
expanded membraneous hairs are reticulated, whereas in ocellatus 
they are irregularly branched. 

The stigmata and stigmatic hairs (or organs), which are hidden 
in palmicinctum, are present and conspicuous in ocellatus ; the organs 
are somewhat lancet-shaped. Another great difference is the 
entire absence in the present nymph of the four immensely long 
hairs which project round palmacenctum. 

In other respects than those above named the same description 
would serve for both species, although the adults are so different. 

I have only found the species upon the yellow lichens which 
clothe the granite rocks of the Land’s End, Cornwall; it is not 
common even there. 


Noraspis LicnopHorvs,| ”. sp. Pl. II. Figs. 7, 8. 


Average length about *19 mm. 
Ae breadtits, =) alice. 
Me length of legs, Ist and 4th pairs, about -1 mm. 
ai s 


” ” ” r ” ” ” 


* Described in this Journal, iii, (1880), p. 184. 
+ Arxvoy, a fan; pepw, I bear. 


Further Notes on British Oribatide. By A. D. Michael. 11 


This extremely minute species is principally distinguished by 
the disproportionately large size and unusual shape of the stigmatic 
organs, from which I have named it. 

The colowr is light yellow-brown, and the whole dorsal surface 
is highly polished. 

The cephalothoraz is considerably narrower than the greatest 
width of the abdomen, but at the actual point of juncture the 
cephalothorax is slightly the wider, and is partially hidden by the 
advancing anterior point of the latter. There is a small central 
point to the rostrum, which then has a very obtuse angle, and, 
after attaining nearly its full width, becomes more parallel-sided. 
The cephalothorax widens suddenly at the anterior edge of the 
tectum, which projects beyond the lateral margin of the rostrum. 
The central portion, or tectum proper, although attached to the 
cephalothorax by its whole surface, has the position of the lamellz 
marked by two strong ridges joined by a transverse ridge anteriorly, 
and also joined posteriorly, not far from the abdomen, by another 
ridge, not straight, but forming three angles, the central pointing 
backward, and the two lateral ones pointing forward ; after these 
join the ridges which represent the lamelle, the two united ridges 
turn sharply inward to escape, and border, the inside of the 
stigmatic elevation. The stigmatic organs are of moderate length, 
very broad, and flattened out, and resemble the Japanese or Indian 
fans, only that the distal margin is slightly wadulated; these 
organs are marked with lines of elevated dots, and from their large 
surface they are blown about a little by the wind. 

The legs are of moderate length, the second joints very thin at 
their insertion, but suddenly, and much enlarged, narrowing again 
somewhat at the distal end; the third joints very small and fine ; 
the tibize wineglass-shaped, much enlarged at the distal margin ; 
the tarsi short and stout, the triple claws very heterodactyle. 'Vhis 
latter point, according to Nicolet’s definition, would prevent the 
creature being included in the genus Notaspis. ‘The tibie of the 
first pair of legs have the tactile hair long, the tarsi have numerous 
fine hairs, and there are one or two short spatulate hairs on each of 
the other joints of each leg. 

The abdomen is elliptical, pointed anteriorly and posteriorly, the 
anterior point being the sharpest. ‘There is a close row of short, 
curved spatulate hairs round the margin, and two longitudinal 
rows of about three similar hairs near the centre of the 
notogaster. 

I have found the creature in decayed wood at Tamworth, in 
Warwickshire, and at Epping Forest; it isnot common. I believe 
it to be unrecorded. 


12 Transactions of the Society. 


Nymph. 


The nymph of this species so closely resembles the perfect form 
that I do not think any one would mistake it. I therefore have 
not figured it, and only give here the differences from the perfect 
form (beyond the ordinary one of being monodactyle instead of 
tridactyle). 

The colour of the nymph is pure milky white, without a speck 
of darker marking about it. 

The general thickness of the legs is greater in the nymph, and 
the shapes of the respective joints are not so varied. 

The markings figured upon the cephalothorax of the adult are 
not found on the nymph. 

The hairs bordering the abdomen are rather smaller in the 
nymph than in the adult. 

The skin is covered with slight wrinkles or vermiform markings 
instead of being polished. 


Noraspis Lacustris, ». sp. Pl. II. Fig. 6. 


Average length about *5 mm. 
3 breadth ,, ° A; 
is length of legs, Ist pair, about *26 mm. 


” 3 4t ” » 4 by 


I have ventured to include this species in the genus Notaspzs, 
although this is a monodactyle species, and Nicolet defines the 
genus as tridactyle; but I have come to the conclusion that, 
although it was perfectly natural for Nicolet, working from the 
species he was acquainted with, to take the number of claws as dis- 
tinctive of genus, yet there are some genera in which this cannot 
be supported as a good characteristic. 

This species is strictly aquatic, but is not a swimming creature ; 
indeed, none of the Oribatide are. It crawls about the subaqueous 
plants, and is confined to fresh water. It is often found covered 
with diatomacese, which adhere to it sufficiently tightly to be 
preserved upon it. ' 

The colour is dull reddish-brown ; the texture is smooth but not 
polished. 

The cephalothoraz is less than half the length of the abdomen, 
and forms a broad, short cone, with a slightly rounded apex; it is 
considerably rounded at the posterior angles. The base is almost 
as wide as the anterior margin of the abdomen. ‘There are not any 
markings on the dorsal surface, except two short ridges, which are 
doubtless the homologues of the wings of a tectum, but otherwise 
that part is absent. The stigmatic organs are not visible, and 
there are not any interstigmatic hairs; the rostral hairs are short 
and curved. 


Further Notes on British Oribatide. By A. D. Michael. 13 


The legs of the first two pairs are set in deep clefts of the pro- 
jecting lateral portions of the sternum; they have a tendency to 
set outward. The second and fourth are the principal joints, the 
tarsi being short and thick. Hach tibia bears a long tactile hair ; 
the tarsi have numerous fine hairs, and the other joints, except 
the coxee, mostly have a few longish, fine hairs, chiefly arranged in 
whorls. 

The abdomen is a short ellipse, not far from a circle, and is very 
slightly truncated posteriorly. This truncated portion bears 
two pairs of short, fine hairs, the inner pair being the longest. 

I believe I know the nymph of the species, but as I have not 
actually bred it I refrain from describing it. 

The species is common and generally distributed. 


ScUTOVERTEX MACULATUS,* 7. sp. PI. I. Figs. 1-5. 


Average length about ‘54 mm. 


. breadth ,, ‘30 ,, 
. length of legs, Ist and 4th pairs, about °33 mm. 
9 ” 2nd ” 3rd ” ” 30 ” 


The colowr both of body and legs is dark brown, almost black ; 
the whole dorsal surface is thickly sprinkled with raised dots. 
These are irregular in shape, and in scattering on the cephalo- 
thorax, but on the abdomen, which constitutes by far the larger 
portion of the creature, they are more even in size and arrangement, 
being closely packed, and more or less approaching round or 
subsquare. Towards the lateral and hind margins of the abdomen 
these dots form lines of dots radiating from the centre of the body, 
along the front margin they are transverse in arrangement, and 
in the centre they are irregular, or form labyrinthine lines. These 
dots projecting make the edge, or any part seen against the light, 
always appear rough. 

The shape of the creature is an elongated ellipse, being nearly 
twice as long as broad. 

The cephalothoraz is broad and rather large, but is greatly 
overhung by the anterior margin of the abdomen, which hides a 
large part of it. The extreme tip of the rostrum is small and 
rounded, and bears a pair of hairs. From thence the cephalothorax 
widens suddenly, and becomes much arched, and again widens 
somewhat suddenly at the insertion of the first pair of legs. There 
is a tectum very conspicuous, but short and narrow, and without 
lateral wings, or rather the edges are thickened, slightly raised, 
and then turned downward, giving an appearance of being 
attached to the cephalothorax by their whole circumference. 

From about the middle of the internal edge of the lateral ridge 


* Maculatus, spotted. 


14 Transactions of the Society. 


of the tectum, on each side, another ridge starts and runs backward 
at an angle, so that the two together form a V-shaped marking, the 
point of which is rounded, and lies within an indented semicircle in 
the anterior margin of the abdomen. The elevated markings on 
the tectum form transverse wavy lines. There is a strong chitinous 
projection from the side of the cephalothorax between the second 
and third pairs of legs. The stigmata are near the lateral margin 
between the first and second pairs of legs. The stigmatic hairs 
are short, and consist of a small globular head, on a stout filiform 
peduncle. There are two pairs of short, thick hairs on the dorsal 
surface of the cephalothorax. 

The coxz of the first two pairs of legs are hidden beneath the 
body. The trochanters of the same pairs are large and long, but 
suddenly become small, and turn almost at right angles near their 
insertion into the coxee. The coxe of the third and fourth pairs of 
legs are rounded and conspicuous. ‘The second and fourth joints 
are the longest in all the legs, the third joimt being the smallest. 
The first three joints in each leg are covered with irregular raised 
markings. ‘The tarsi have a few fine hairs round the claws, which 
are very heterodactyle. There are three short, thick hairs on the 
fourth joint of each leg of the first two pairs, and a few other 
similar hairs on the different joints of the legs. All these hairs are 
very caducous. 

The abdomen is elliptical, slightly pointed posteriorly, and 
slightly truncated anteriorly ; it is indented between the insertion 
of the third pair of legs and the stigma, and the anterior margin is 
cut out in rather more than a semicircle. This indentation receives 
the point of the V-shaped ridge on the cephalothorax; and at the 
side of it the anterior margin of the abdomen is attached to the 
upper surface of the tectum. There are about ten short, thick 
hairs round the hind margin of the abdomen, also very caducous. 

On the ventral surface the genital plates form almost a square, 
and are far forward. Theanal plates are large, elliptical, and touch 
the posterior margin. i 

Nymph. 


The colour of this curious nymph is dull opaque brown, often 
with a shade of dark olive green in the brown. It is so broad and 
flat in general shape as to give the effect of having been 
flattened out, and it is thickly covered with wrinkles and ridges all 
over. 

The cephalothoraz is flat, long in proportion to the abdomen, 
but not in proportion to its breadth, conical, but sharply excavated 
at the edge, for the insertion of the first pair of legs. The base of 
the cephalothorax is narrower than the anterior margin of the 
abdomen, and the second pair of legs are inserted in the angles thus 


Further Notes on British Oribatide.. By A. D. Michael. 15 


formed. The cephalothorax bears a complicated series of ridges 
not easy to describe, and which will be best understood by reference 
to the drawing. I will, however, endeavour to give an idea of their 
arrangement in words. ‘The median (or axial) portion of the 
vertex is divided into three spaces bordered by strong raised ridges. 
The anterior one is trapeze-shaped, with the small end foremost and 
coming near to the point of the rostrum, but not reaching it. Two 
short ridges, however, run from the anterior angles of the trapeze, 
one to each side of the rostrum, very near to the point. The ridge 
which forms the posterior border of the trapeze forms the anterior 
border of a hexagon, which has curved sides, convex inwards, the 
anterior side being the longest, and the two next sides very short. 
The posterior ridge of the hexagon forms the anterior margin of an 
oblong or elliptical figure, usually somewhat constricted in the 
middle. This figure extends back on to the abdomen, so that it is 
difficult to say where the abdomen commences in the median line. 
From the central angle on each side of the hexagon a short trans- 
verse ridge runs about half-way towards the lateral margin. From 
its termination a ridge runs forward to the front of the excavation 
for the first leg, and another, or continuation of the same, runs 
back toa circular ridge surrounding the stigma, and from the stigma 
a triangular space bordered by another ridge extends to the lateral 
margin. The stigmatic organs are short, globular, on a short 
peduncle, and very white. ‘he interstigmatic hairs are absent or 
little seen ; the rostral hairs are present. 

The legs are stout and gradually diminished towards the end. 
The third and fourth joints of the two front pairs each bear a strong 
serrated spine on the upper side; the other hairs on the legs are 
short, and the tactile hair is absent. 

The abdomen is flat in general effect, but has somewhat raised 
anterior and lateral edges, and is raised to about the same extent 
along the median portion, being slightly arched there; between 
this median portion and the lateral edge is a depressed channel. 
The whole abdomen is covered with wavy closely-set irregular 
wrinkles. Three or four of these run along the anterior, and about 
half-way down the lateral margin; the centre of the space enclosed 
by these last-named wrinkles is occupied by a set of wrinkles 
bending strongly forward. Behind them the wrinkles become 
more transverse, until near the posterior margin, where they again 
bend strongly forward. The posterior margin is set with eight 
spatulate hairs, of which the two lateral pairs are very short, the 
two central pairs much longer and directed inward, the central pair 
crossing. 

I have only found the species on the lichen near the sea-shore, 
at the Land’s End, Cornwall. It has not to my knowledge been 
recorded before I found it, and it is not common. 


16 Transactions of the Society. 


Damzus moniipzs, n.sp. Pl. II. Figs. 1-5. 


Average length about 34 mm. 
+ breadth 5, “1/8 ., 
Bs length of legs, 1st pair, about °17 mm. 
A 3) 2nd and 3rd pairs, about ‘15 mm. 
a ¥5 4th pair, about *19 mm. 

This is an extremely minute but rather elaborately formed 
species. I have included it provisionally in the genus Dameus, 
_ but that genus will probably require division—perhaps by reviving 
Koch’s genus Oppia, and properly defining it, in which case the 
present might well serve for a type-species. The colour is rather 
light brown, and has a whitish shade over some of the raised parts. 
It is not very strongly chitinized, and is indeed rather more leathery 
in texture than most of the family, except the genus Nothrus, and, 
like many other Orcbatid# which have this texture, and are thus 
not as fully protected as harder species, it makes up for the 
deficiency by covering itself with dirt to such an extent that it is 
almost impossible to get it clean, its very small size being an addi- 
tional difficulty. The figure and this description are taken from a 
carefully cleaned specimen, otherwise many of the details would not 
be seen. Another source of error, which must be avoided in iden- 
tifying the species, is that the elevations on the dorsum of the 
abdomen are apt to lose their form and be very difficult to see 
shortly after death, particularly if treated with reagents. By care, 
however, the true form may be preserved. 

The division between the cephalothorax and abdomen is very 
marked. The actual rostrum is short and conical, not a third of 
the length of the dorsum of the cephalothorax. Behind this the 
cephalothorax is covered by a tectum or its homologue, but the 
whole of it is anchylosed to the surface of the cephalothorax, and 
does not stand free. The lateral edges are straight or slightly con- 
cave, but very rough. The anterior edge is rather convex; the 
wings of the tectum are well marked, and are also anchylosed to 
the surface of the cephalothorax; they are reflexed, sloping 
downwards on the side of the cephalothorax. A strong ridge runs 
along the juncture of each wing with the tectum, and this ridge 
projects forward beyond the edge of the tectum, forming a strong, 
rough, curved point, terminated by a hair; indeed, it seems to have 
taken the place of the projection frequently found at the anterior 
edge of the wing. The whole tectum is reticulated, but the reticu- 
lations are not easily seen on the wings. Behind the juncture of 
the tectum the cephalothorax rises suddenly, and forms a rough 
central lump, at the edges of which are the stigmatic tubes pro- 
jecting to an unusual degree, the stigmata opening at the extreme 
edge of the body. The stigmatic organs (or hairs) are long, 
spatulate, rough, and point upward, outward, and backward. 


Further Notes on British Oribatide. By A. D. Michael. 17 


There is a deep depression between the hinder part of the cephalo- 
thorax and the abdomen. 

The legs are very remarkable, or at least the first pair is. 
They are by no means so long as is usual in the genus Dameus, 
and the forms of the pieces are singular. The coxe are not visible 
from the dorsal aspect, and the expansion of the cephalothorax 
above mentioned has a deep cleft to admit the upward motion of 
the thin proximal end of the so-called trochanters of the first pair of 
legs. This joint is greatly enlarged. The first two pairs of legs 
have the so-called femurs very short, with a short, thin, proximal, 
and a much broader, almost square, distal end. The tibize of the 
first pair of legs are the pieces which render the legs exceptional ; 
they are globes which appear disproportionately large, and are 
borne on extremely short and very thin proximal ends. The tarsi 
are all pyriform, and thickly clothed with hairs. ‘The enlarged 
tibia bears a long tactile hair. 

The abdomen is elliptical, slightly pointed posteriorly, and 
strongly truncated in front; its antero-lateral angles are produced 
into well-marked points, which curve towards the stigmata, so that 
from the dorsal aspect two open spaces are seen, bounded on the 
outside by these points, and anteriorly by the coxe of the third 
pair of legs. Immediately behind the anterior margin there is a 
broad, rounded, transverse elevation, not reaching the lateral 
margin. Behind this is a deep, linear depression, and then the 
centre of the abdomen, until within a quarter of its length from 
the hind margin, is occupied by a domed lump, followed by a 
smaller one, which touches the hind margin. Exterior to these 
elevations the abdomen is a broad, almost flat, expansion, which 
seems to form a flat annulus round the central elevation. At the 
extreme edge of this is a narrow, rough ridge. The annulus curves 
downward towards the margin, but not very strongly. The whole 
surface of the abdomen is rough and irregularly sprinkled with 
raised dots, which are far largest and most conspicuous on the 
central lump. 


The Nymph. 


This is also rather a complicated creature, not very easy to 
describe. The colour is light oak-brown, with a tendency to a 
grey dusty effect over the raised parts of the skin. The texture is 
a little like fine shagreen, and the general outline is a shield-shaped 
abdomen surmounted by a bluntly conical cephalothorax. 

The cephalothorax is rather more than one-third of the whole 
length; at its base it is nearly as wide as the abdomen. The 
rostrum is rounded anteriorly, and slightly truncated. A blunt 
point on each side of the truncation carries the curved rostral hair. 
The cephalothorax appears arranged in three spaces, which, com- 

Ser, 2.—Vot. II. © 


18 Transactions of the Society. 


mencing anteriorly, are, first, the rostrum, which bears two longitu- 
dinal ridges commencing close to the above-named points, but 
sometimes a trifle nearer the lateral margin; the second division 
extends from the rostrum to the insertion of the first pair of legs, 
and has a central shield-shaped space on the dorsal surface, enclosed 
by a raised ridge, against the front of which the ends of the before- 
named longitudinal ridges abut. A smaller space, narrower in 
proportion, on the slope of each side, is also enclosed by a ridge. 
‘The third portion of the cephalothorax extends to the abdomen, and 
has a central octagonal space enclosed by a similar ridge, abutting 
on the shield-shaped ridge anteriorly, and on the abdomen. pos- 
teriorly. On each side of the octagon is a rounded, somewhat 
mamillar portion, bearing the stigma, which is dorsal. The stig- 
matic organs (or hairs) are long, filiform, rough, and sinuous. The 
interstigmatic hairs are apparently absent. 

The degs are rather short, of almost even thickness throughout, 
rough, and with a projecting point on the front tibiae, which bears 


a very strong tactile hair. The other joints each have a pair of 


short, curved, spatulate hairs. ‘The tarsi are short and thick, and 
clothed with numerous fine hairs. 

The abdomen carries the cast notogastral skins stretched quite 
flat on the back, except that the edges of each skin have curled up 
and form ridges, thus, in the full-grown nymph there are three 
almost concentric ridges. Within the space enclosed by the inner 
ridge—i.e. upon the larval skin—are three hemispherical knobs, 
arranged longitudinally. ‘There are two projecting points at the 
posterior end of the creature, and of each cast skin, and each point 
bears a long, spatulate, curved hair. 

The creature lives in decayed wood. I first found it in some 
material brought from Yorkshire by the Rey. H. Tattershall, 
and I have since found it myself in Hopwas Wood, near 
Tamworth. 


ee, -o- 


( 19 ) 


IL—A New Growing or Circulation Slide. 
By T. Caarters Wuirz, M.R.C.S., F.R.M.S. 
(Read 14th December, 1881.) 


TcrEastnG attention has of late years been devoted to the subject 
of slides by which the development of microscopical organisms can 
be observed, but the majority of the forms suggested have been 
attended by various drawbacks and disadvantages in their design 
and construction, leading to their disuse. The one here described 
seems to be as efficient as can be desired; it is, however, merely 
put forward as a suggestion, and I do not venture to claim for it 


more than simplicity and efficacy to recommend it to microscopical 


observers. 

It often happens that in examining a gathering from some 
aquatic source an organism is met with about which the observer 
would desire to know more, but to transfer it from his slide to 
one of the growing slides in ordinary use would probably result in 
its loss or destruction. The slide now described is designed to 
supersede the use of the glass slip generally used for this examina- 
tion, so that should such an organism present itself all that is 
required to maintain a constant current is the insertion of threads 
of cotton into openings in the sides of the cell. The organism is 
then duly nourished, and no alteration occurs to interfere with ~ 
ie proper development, which can be readily noted from time to 
ime. 

The slide (Fig. 1) consists of the usual glass slip AA 
(3 in. x 1in.), having a narrow ledge of glass B (about } inch 


iniees, Il. 


wide, and extending nearly its whole length), cemented to its 

lower border with marine glue; to this is cemented at right angles 

a strip of thin covering glass C, about + inch wide and about 

13 inch from the end of the slide, having a narrow channel cut 

through it for the passage of an intake thread D. A similar strip 
0 2. 


20 Transactions of the Society. 


B, having a like cut through it for the passage of an outlet thread 
F, is cemented at the same distance from the opposite end of the 
slide. In this condition the slide being filled with water to the level 
of G, any current coming in through the intake thread D would 
pass directly across the top of the water in the cell, and pass out 
by the outlet thread F, and organisms near the bottom of the cell 
would not be benefited by a change of water; I therefore cement 
a very narrow slip H of the same covering glass as before to the 
inner side of the outlet end of the cell, commencing at the top of 
the slide, and extending to very nearly the bottom, so as to leave 
about ;!, inch between E and H. If the intake thread is connected 
with a bottle of water placed above the level of the slide, water 
entering by the intake thread will pass in a diagonal direction 
from D to the left and bottom of the cell, where the influence of 
the suction set up by the siphon-like action of the outlet thread 
makes itself felt, and there is a regular current in the direction 
of the arrows. 

The front of the cell is formed of a piece of thin covering glass 
of 1}inch by §,and two small square blocks of glass I, cemented on 
each side, will hold this covering glass sufficiently firm to prevent 
it sliding on the organism and crushing it. 

Such a growing slide will hold about 1 drachm of water, and 
taking the rate of the drops from the outlet thread as about one 
per minute, the whole of the water in the cell is changed once in 
an hour, while at the same time the current is not sufficiently 
strong to carry away more than the finest and lightest bodies.- It 
allows of fair observation with a -inch objective, and if desired 
could be made with thinner glass, so that a 2-inch or g-inch might 
be used. 


ee 


( 21 ) 


IIl.—On a Hot or Cold Stage for the Microscope. 
By W. H. Symons, F.R.MS., F.CS. 
(Read 14th December, 1881.) 


Tuis stage consists essentially of a copper or brass box A, Fig. 2, 
8 cm. long, 5 cm. broad, and 1°5 cm. deep; an open tube F, 
5 x 2 em., communicates with the interior, and allows of the 
expansion of the contents and for filling. In the upper and lower 
sides of the box are apertures H, for the passage of light, 2 em. 
in diameter, the lower covered by a thin glass cover, 2:5 cm. in 
diameter, and the upper by one which constitutes the working 
stage, 3°5 cm. in diameter. Both covers are kept in position 


Hig. 2: 
E £ —— 
ie SS is 
(Sy, 2S ee paar ie Tigo és 
| SF bi _y fF — EW TRANEE TOR COOTER? 
ao * =e 
ee e|| ENTRANCE FOR HEATER 


between pairs of vulcanized rubber rings by means of brass plates 
D, clamped on with screws H, the plates being furnished with 
apertures slightly smaller than the thin covers. A thin copper 
ipe BB, 5 mm. in diameter, is carried round the bottom of the 
inside of the box A, one end being forked, and all three branches 
furnished with taps. ‘This pipe serves to convey the heating or 
cooling agent to the water or other liquid contained in the box. 

The temperature is ascertained by means of a thermometer C, 
having its bulb bent in a circle slightly smaller than the aperture 
for light; it is placed in the box with the bulb almost touching the 
upper thin glass cover. Between the thermometer and the copper 
pipe is a copper partition, having a number of slots in its base to 
allow of the circulation of the water. In this way the thermometer 
is protected from undue heat, and as all water which reaches the 
upper thin glass must pass it, a very near approximation to the 
temperature of the object upon the thin glass is obtained, espe- 
cially if the object is protected from currents of air by a cardboard 
shade. 

The most convenient heating agent is steam, a small flask 
100 c.c. capacity will work for over an hour, and the temperature 
may be varied from normal to 95° C. at pleasure; steam, however, 
gives out its latent heat immediately on coming in contact with 
the tube, and therefore that portion of the box or bath nearest to 
the supply becomes warm very much sooner than that further 


22 Transactions of the Society. 


from it; if great exactness be required steam can be replaced by a 
current of warm water or saturated solution of chloride of calcium, 
which give out only specific heat, and that nearly equally through 
the whole length of the tube. In either case the box is filled with 
recently boiled distilled water or a saline solution, and placed, with 
a non-conductor intervening, upon the stage of the Microscope, so 
that the optic axis corresponds with the centres of the apertures ; 
one of the forked tubes is then connected with the hot fluid, the 
other with a supply of ice-cold water, and the exit end of the 
copper tube with an empty vessel. The object is now placed upon 
the thin glass stage, covered with another thin glass, and sur- 
rounded with a cardboard shade and focussed. The heating agent 
is circulated through the copper pipe until the required tempera- 
ture is attained, the tap can be then turned off, and if a sudden 
reduction of temperature be necessary the tap which communicates 
with the cold water turned on. 

Ifa temperature above the boiling-point of water be required, 
the box is filled with glycerine, and the heat from a gpirit-lamp 
conveyed to it by means of a projecting copper plate, one end 
being in contact with the bottom of the box, the other in the flame 
of the lamp. In this way any ordinary temperature can be 
obtained, but it is not so completely under control as the steam, 
there being a rise of some 10° after removing the source of heat. 

If a very low temperature is wanted, all the metalwork is 
covered with felt, and the box filled with clean crystals of ice and 
salt and water. 

This stage is specially adapted for those cases where a rising 
or falling temperature is required. It was originally contrived 
for studying the tumefaction of starches, noticing the temperature 
at which the various granules burst, but I have found it useful 
also for ascertaining roughly the melting-points of fats, by 
observing when the crystals in them disappear; and for jellies, 
resins, and other structureless, easily fusible, substances, by noticing 
when small particles assume the liquid form; and it will obviously 
have many other applications. 


Peketir rica, triks 


( 23 ) 


SUMMARY 


OF CURRENT RESEARCHES RELATING TO 


ZOOLOGY AND BOTANY 


(principally Invertebrata and Cryptogamia), 


MICROSCOPY, &c., 


INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* 


ZOOLOGY. 


A. GENERAL, including Embryology and Histology 
of the Vertebrata. 


Photographs of the Developmental Process in Birds.j —C. 
Kupffer and B. Benecke give fifteen photographic plates of the 
embryos of birds, with full descriptions, the outlines of the photo- 
graphs being drawn on transparent paper, on which the necessary 
lettering is placed. A full description of the photographic apparatus 
is given, and it is stated that osmic acid was found to give to the embryos 
a colour suitable for photographic reproduction. When whole embryos 
are reproduced, the amplification is ten, and when one or other end 
only is photographed, it is twenty times. Some of the photographs are 
particularly good, and the tracings form admirable diagrammatic 
representations of the different relations of the parts. An important 
fact to which attention is drawn is, that within the limits of one 
species variations have been found to be much more marked in the 
earlier than in the later periods. 


Development of the Paired Fins of Elasmobranchs.t — Mr. F. 
M. Balfour states that in Scyllium these arise as slight longitudinal 
ridge like thickenings of the epiblast, and that in Torpedo the ante- 
rior and posterior are on either side transitorily connected together 
by a line of columnar epiblast cells. Later on, the fins become a 
ridge of mesoblast covered by epiblast ; the embryonic muscle-plates 
grow into the bases of the fins,and form two layers, while in the 
intermediate indifferent mesoblast changes begin to be set up, which 
give rise to the cartilaginous skeleton. There is thus formed in the 
fin a bar which springs at right angles from the posterior side of the 

* The Society are not to be considered responsible for the views of the 
authors of the papers referred to, nor for the manner in which those views 
may be expressed, the main object of this part of the Journal being to present a 
summary of the papers as actually published, so as to provide the Fellows with 
a guide to the additions made from time to time to the Library. Objections and 
corrections should therefore, for the most part, be addressed to the authors. 
(The Society are not intended to be denoted by the editorial ‘‘ we.”) 

+ Nova Acta Acad. Czes, Leop.-Carol. Germ, Nat. Cur., xli. i. (1879) pp. 149-96 
(1 pl. and 15 photos.). 

} Proc. Zool. Soc. Lond., 1881, pp. 656-71 (2 pls.). 


24 SUMMARY OF CURRENT RESEARCHES RELATING TO 


pectoral or pelvic girdle, and runs parallel to the long axis of the 
body. The free end of the bar begins to undergo segmentation into 
rays, and much of this is effected “before the tissue of which the 
plates are formed is sufficiently differentiated to be called cartilage by 
an histologist.” 

We have then a longitudinal bar along the base of the fin, which 
gives off perpendicularly a series of rays which pass into the fin. It 
is pointed out that, from its position this basal piece can never have 
been a median axial bar with rays on both sides. The resemblance 
to the arrangement of the unpaired fins is consequently very striking, 
and support is given to the author’s original doctrine of a once 
continuous lateral fin. 


Development of the Sturgeon.*—In continuation of his previous 
paper, Professor W. Salensky points out that in this fish it is very 
difficult to fix the limits between the period of the formation of the 
embryonic layers and that in which there appear the earliest rudi- 
ments of the organs. Here we find that the envelopment of the 
inferior by the superior portion, and the further differentiation of the 
embryonic layers is contemporaneous with the appearance of some of 
the organs in the mesoblast. Dealing with the modifications under- 
gone by the egg up to the point at which the medullary groove 
becomes closed, the author states that organs begin to appear at the 
termination of the first day of development. On the second day a 
groove 0:7’ in length appears in the middle of the embryonic area. 
The posterior extremity of this groove corresponds exactly to the 
blastopore. In the next stage the anterior end of this primitive 
groove dilates to form the rhomboidal rudiment of the brain. The 
hinder part of the groove opens directly into the primitive digestive 
cavity by means of the blastopore, and it is only near the end of the 
period of development that the union between the digestive and 
medullary cavities ceases to exist. Meantime, the lateral parts of the 
embryonic area have been undergoing important changes. On either 
side there appears a white band which behind diverges slightly 
from its fellow. These are the first indications of the Wolffian ducts ; 
and the parts internal to them become modified to form the vertebral 
plates, and those external to them the lateral plates. 

Previous, however, to the appearance of the groove on the surface 
of the embryonic area, important changes have been taking place 
within. There has appeared an axial thickening, formed from the 
ectoderm and mesoderm, which has an intimate connection with the 
formation of the notochord and of the central nervous system. These 
changes are described in detail. The mesoderm becomes divided into 
a median and lateral portions; the first constitutes the notochord, 
while the side pieces give rise to various organs. After the appear- 
ance of the medullary groove we may distinguish a central portion in 
which the groove is placed, and lateral parts which are distinguished 
by having over them the enveloping lamella. The bases of the cells 
which form the floor of the groove are strongly pigmented, and this 


* Arch. de Biol., ii. (1881) pp. 279-341 (4 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 25 


pigment is derived from the ectodermal cells which become confounded 
with the cells of the medullary plates. 

The further development of the nervous system consists in the 
progressive development of the lateral pieces which correspond to the 
medullary plates of other Vertebrates. Atabout this stage the parts of 
the mesoderm give rise to the excretory organs. 

After the medullary groove becomes closed it is possible to dis- 
tinguish a cephalic from a trunk region, and the boundary between 
the two corresponds to the anterior ends of the Wolffian bodies. 
Owing to the transparency of the embryonic area it is possible to see 
that the trunk grows by a gradual increase in the number of the 
primitive segments. Having before had five somites, we see these 
last increase as changes go on in the form and position of the blasto- 
pore. While the anterior segments retain their perpendicular position, 
the posterior become inclined to the longitudinal axis, to return later 
on to their primitive position. While elongation is proceeding, the 
trunk becomes thicker, the dorsal region increases in size, and there 
is exhibited a slight inclination to the right, the appearance of which 
causes a certain asymmetry in sections taken at this period. 

Soon the blastopore closes, and its position is marked by an accu- 
mulation of pigment. The rudiment of the tail becomes visible by 
the formation of a tubercle; the cephalic extremity possesses two 
vesicles, and the mesoderm is still thin anteriorly. Where the 
cephalic plate enlarges, a central and a peripheral part may be distin- 
guished, the branchial clefts begin to appear, and a facial process is 
developed in front of the head. The heart does not commence to con- 
tract till the end of the period of embryonic development, and its 
contractions are at first very slow. Simultaneously with this the 
veins and their ramifications appear. 

The author next proceeds to a study of the development of the 
internal organs with which he considers the modifications of the 
embryonic layers. He points out that the ectoderm consists of two 
layers, of which the superior is, at first, strongly pigmented ; through- 
out its development its cells nearly all retain their original flattened 
character ; the lower layer is that which contributes most largely to 
the formation of the sensory organs in which, except in the case of the 
olfactory fosse, the outer layer takes no part. After describing the 
details of the development of the central nervous system, Professor 
Salensky raises the question of the homology of this region with 
the nervous system of Vermes and Arthropoda. He points out that 
(1) the central nervous system of all Vertebrates is formed from 
two thickenings of the ectoderm, set parallel to the long axis of the 
body: that of all Articulates has a similar origin. (2) In some cases, 
e.g. Echiurus, the “ Articulates” present a median groove comparable 
to that of Vertebrates. (8) The formation of the medullary groove 
commences, in the case of both phyla, posteriorly, and is continued 
forwards. On the other hand the Vertebrata have the central neryous 
system dorsal in position, and the medullary groove becomes closed. 
As to the first of these, he points out that the position of the mouth 
is the determining character, in conjunction with that of the loco- 


26 SUMMARY OF CURRENT RESEARCHES RELATING TO 


motor organs; these points he looks upon as having less morpho- 
logical value than the development of the system, and its correlation 
with other organs during the course of development. The closure 
of the medullary groove is regarded as being merely the result of 
further modifications. 

If we accept the general homology, we have next to determine 
how the parts correspond; the author cannot follow Dohrn and 
Hatschek in regarding the homology as being complete; he looks 
upon the brain of Vertebrates as being a new formation, which is 
their exclusive property; it merely consists in an elongation and 
dilatation of the already existing nervous system, or in other words 
the medulla, which is the analogue of the ventral ganglionic chain of 
the Articulata. ; 

The mesodermal derivates are dealt with in great detail, and a 
comparison with what is seen in Plagiostomi leads the author to say 
that they approach the higher, while the Ganoids approach the lower 
Vertebrata ; and this portion of the essay concludes with an account 
of the development of the enteric tract. 


Development of Petromyzon Planeri.* — J. P. Nuel directs 
attention to the phenomena of the contractility of the ovum: imme- 
diately after impregnation, before which the vitellus was everywhere 
closely applied to the chorion, the yolk commences to contract, till 
at last it is at all points separated from its investment. Calberla 
regarded this as being due merely to osmotic action, but the fact 
seems te be that a contractile wave, starting from the active pole, 
slowly but gradually passes over the whole of the yolk; this takes 
about twelve minutes to be effected. 

From the moment when the egg begins to segment there is 
a period of rest between each division, and this period shortens 
as development advances; when the segmentation period is at 
an end the cells of the hypoblast are in repose for a lengthened 
period, while the epiblastic cells, continuing to divide, give rise to 
an epibolic invagination. At a certain period most of the hypoblastie 
cells start into activity, and the elements of the digestive tract begin 
to be formed ; some of them, however, still remain quiet, and, only 
later, give rise to the liver. When a group of cells enter into 
activity, their calibre diminishes, and the yolk-grains are fused 
together. 

After describing the details of the development of the digestive 
tract, M. Nuel states that the transformation of the yolk-spheres 
first takes place along the axis of the embryo; commencing at the 
anus of Rusconi, it rapidly extends forward; being most intense at 
the point where the epiboly is most advanced; thence it widens out, 
and gradually invades the whole surface of the hypoblast, till it 
comes into contact with the segmentation cavity. 

When the mesoblast developes, it is clear that it has no relation 
to the chorda dorsalis ; for the two are simultaneously differentiated 
from a common embryonic layer, which, later on, also gives rise to 


* Arch, de Biol., ii. (1881) pp. 403-54 (2 pla.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 27 


the secondary hypoblast; the mesoblast in Petromyzon, just as in the 
Sturgeon (Salensky) is developed from behind forwards. 

The chapter on the germinal layer is largely occupied with a 
criticism of the observations of W. B. Scott; and the author con- 
cludes by giving his adhesion to the doctrine of His, that the study 
of the mechanical causes which affect the embryo, and the causal 
connection of the changes which take place in the egg are the true 
objects of embryology, and he points out that this side of the study 
is to descriptive embryology what physiology is to zoology. 


White Corpuscles of the Blood.*—M. Renaut describes the 
different forms presented by the white corpuscles in different animals. 
In the Crayfish, besides the ordinary lymph-corpuscles, there are 
many larger bodies with well-defined nuclei, the protoplasm of which 
contains large highly refracting granules, resembling in many 
respects the vitelline granules of the Frog and other Batrachia. These 
corpuscles have a sharply limited, but thin exoplastic pellicle; and if 
a drop of such lymph be allowed to fall into a drop of a 1 per cent. 
solution of osmic acid, the white corpuscles are instantly fixed, with 
their pseudopodia or protoplasmic processes extended; and these 
processes can then be seen to perforate the thin membrane, now black- 
ened with the acid. There are thus two kinds of white corpuscles in 
the Decapod Crustacea—the lymphoid corpuscles and the amceboid 
corpuscles. 

Do similar differences exist in the blood of Vertebrata ? 

In reply to this, M. Renaut states that in the blood of all the 
Vertebrata, from the Cyclostome to the Saurians, the white corpuscles 
are of two kinds; one, the ordinary white corpuscle, composed of 
hyaline protoplasm, presenting many short projecting points, with a 
nucleus undergoing gemmation, and sending forth branched pseudo- 
podia when placed under favourable conditions; the other containing 
numerous brilliant granules imbedded in the protoplasm and sur- 
rounding the nucleus. These resemble the second form of corpuscle 
described above as existing in the lymph of the Crayfish, but differ 
from them in having no outer limiting layer of condensed protoplasm, 
or exoplasm, as Haeckel has named it. The application of osmic acid 
shows that they may be subdivided into two other forms, one closely 
analogous to cells undergoing transformation into fat-cells, which 
present numerous granules, and stain black with osmic acid, and 
another set which contains granules that are not fatty, but which 
stain red with eosin. The best mode of demonstrating the existence of 
these three forms is to fix the blood in the rete mirabile of the capil- 
lary layer of the choroid in the posterior segment of the eye of a frog, 
by removing the anterior segment and exposing it to the vapour of 
osmic acid. At the expiration of twelve hours the eye is removed 
from the vapour, washed, the chorio-capillaris detached from the 
retina, and spread on glass; it is afterwards coloured with, and 
mounted in, hematoxylate of eosin. The corpuscles may then be 
studied, and the three forms of ordinary, granular, and fatty corpuscles 
can be easily distinguished. 

* ¢Science,’ i, (1881) p. 505, from ‘ Arch. de Physiol.’ and ‘ Lancet.’ 


i 


28 SUMMARY OF CURRENT RESEARCHES RELATING TO 


M. Renaut finds that the white corpuscles of mammals generally, 
and of man in a state of health, all closely resemble each other, and 
are of the ordinary kind; but in disease, as in leucocythemia, the 
white corpuscles are not only greatly increased in number, but vary 
considerably in size. Moreover, they are round, and present no 
pseudopodia. They are hyaline, and have a smooth, well-defined 
limiting membrane, and some of them have nuclei which have under- 
gone fission, just as in a cell that is about to segment. Hence, he is 
of the opinion that the white corpuscles multiply and increase in 
number while floating in the blood; other corpuscles may be 
observed, which are charged with granules of some proteid substance, 
resembling vitelline granules, or small masses of hemoglobin ; and, 
lastly, there are still other cells, which are charged with fat. M. 
Renaut has made some observations on the development of the 
red corpuscles of the Lamprey, and gives the following succession of 
forms. White corpuscle with nucleus proliferating and protoplasm 
not limited by an exoplasmic layer; corpuscle with nucleus prolifer- 
ating, the protoplasm forming an uncoloured disk, limited by an 
exoplasm ; corpuscle with proliferating nucleus, protoplasm limited 
by an exoplasm, and forming a disk, more or less charged with 
hemoglobin; red corpuscle with proliferating nucleus; and finally, 
circular red corpuscle, with rounded nucleus. 


Nerve-endings of Tactile Corpuscles.*—W. Krause discusses the 
different views which have been held as to the condition of these 
nerve-endings, viz.:—(1) Langerhaus, who considers that the fibres 
divide di- or trichotomously after entering the corpuscle, and end 
thus by only two or three terminal twigs which may be flattened 
into terminal disks, as is generally the case in the end-bulbs, and 
especially in the round ones. (2) Ranvier, who states of the laminar 
terminal corpuscles of the tongue of water-birds, &c., and of the 
laminar tactile corpuscles, that a terminal disk is interpolated 
between every two of the cells which lie transversely in the bulbs. 
Krause obtained similar results by the use of formic acid and chloride 
of gold. (35) Meissner, from pathological and other observations, has 
set down all the transverse striation to nervous structures, except 
some possibly due to nuclei. But Krause, supported by Fischer and 
Flemming, has explained the large number of transverse nervous 
terminal fibres as due to a spiral course of the latter, accompanied by 
repeated dichotomous branching. 

In order to reconcile the three views, it may be held that 
Langerhaus’ opinion applies to some of the smallest and simplest 
corpuscles; while Ranvier’s apply to their larger and more usual 
forms; whereas Fischer’s preparations show the course taken by 
the terminal fibres in reaching their disks. Krause himself holds 
the inner bulbs to consist of transverse bulb-cells with pale terminal 
nerve-fibres ending in knobbed or discoid terminations between 
them. 


* Arch. mikr. Anat., xx. (1881) p. 215 (1 pl.); and Biolog. Centralblatt, i. 
(1881) pp. 462-3. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 29 


Distribution and Termination of Nerves in the Cornea. * — 
Opinions have differed widely as to the actual mode of termination of 
the corneal nerves, whether singly or by fasciculi in the corneal cells, 
or by reticulations surrounding them. These and kindred questions 
have been investigated by Professor G. V. Ciaccio. He has studied 
animals from all the Vertebrate classes except fishes, and has chiefly 
employed chloride of gold to render the nervous elements visible. His 
results are summed up as follows :— 

1. The nerves of the cornea are of different kinds and have 
different functions, viz. (a) sensitive, some to light and some not, and 
(b) trophic, regulating the nutrition of the tissue. 

2. They form a plexus, the “ circumferential nervous plexus”, at 
the circumference of the cornea before entering it; this consists 
partly of medullated, partly of non-medullated fibres. 

3, This plexus sends out branches and twigs of different sizes in 
various quantities, which enter the cornea, divide and subdivide there 
and form a plexus, the “ primary or principal nervous plexus,” which 
traverses its entire breadth; in the rabbit, mouse, rat, and bat it lies 
chiefly near the anterior face ; in lizards, tortoises, frogs, and tritons 
it is near the middle of its thickness ; in birds it is mostly contained 
in its anterior portion. 

4, Other plexuses exist in this organ, more or less derived from or 
dependent on this chief one; they are termed secondary or accessory ; 
they sometimes lie above, sometimes below the chief one. In the 
frog this plexus lies below the latter, and close to Descemet’s mem- 
brane; in the mouse, it lies above, close to the anterior face of the 
cornea and thus constitutes the “subbasal plexus” of Hoyer and 
others. 

5. The principal plexus gives off a large number of small branches, 
sometimes accompanied by ultimate fibres; they are termed “ per- 
forating branches”; they break up first below the epithelium, each 
into a tuft of fibrils, which form between themselves the “ subepi- 
thelial plexus,” of greater or less closeness, and differently arranged 
in different animals. In the mouse and rat, and perhaps the bat, it 
has a concentric arrangement, but the centre does not correspond to 
that of the cornea. 

6. From different places in the subepithelial plexus fibrils go off 
and enter the epithelium, dividing and anastomosing, and thus forming 
in it a very delicate reticulation, probably broken off here and there, 
(the intra-epithelial rete or plexus of modern authors); the fibres 
terminate either in small button-lke dilatations or simply below 
the outermost cells of the epithelium, which form a delicate mem- 
brane interposed between these endings and the exterior. 

7. The various plexuses and networks thus formed are not to be 
considered as so many distinct units but as so many compound systems, 
each of them being made up of as many parts as there are nerves 
entering into its constitution. Thus, by their distribution over the 
cornea, the nerves form just so many anatomically and physio- 
logically distinct regions as there are trunks and branches of nerves, 


* Mem. Accad. Sci. Ist. Bologna, ii. (1881) 24 pp. (2 pls.)—Sep. repr. 


30 SUMMARY OF CURRENT RESEARCHES RELATING TO 


8. The nervous fibres, both those of the proper substance of the 
cornea and those of its epithelium, always terminate in two ways, 
namely, by plexus or reticulation and by free ending. The latter 
mode, when occurring within the cornea, takes place not only in the 
branching cells but also within or between the fibrous lamin. 

9. The axis-cylinders of the corneal nerves are made up, like the 
fibres of striated muscle, of fibrils, each of which consists of minute 
particles and of a peculiar intermediate substance which unites them 
in linear series; in this case these particles are round, whereas in 
muscle they are prismatic. 


Influence of Food on Sex.*—The results of experiments detailed 
by E. Yung tend to confirm those previously obtained by G. Born, 
who found that when young tadpoles were subjected to special kinds 
of food (in one case vegetable food being given, in another mixed 
vegetable and animal), a large preponderance of females were deve- 
loped. In these experiments there was an absence of what forms the 
chief normal food of tadpoles, viz—marsh-slime, containing various 
organic detritus, rotifers, infusoria, diatoms, &c. 

Yung reared the tadpoles of Rana esculenta in four vessels, feed- 
ing the broods respectively on fish, meat, coagulated egg-albumen, 
and egg-yolk. The percentage of females in each case was 70, 75, 
70,and 71. Ina fifth vessel, out of a brood of 38 tadpoles nourished 
simultaneously on meat, algze, and white of egg (without slime), 30 
were females, six males, and two doubtful. These results seem to 
demonstrate that the quality of the food experimented with exercised 
no distinct influence on the sex, but that a special diet given to young 
tadpoles from the time of hatching favours the development of a 
female genital gland, as Born concluded. 


B. INVERTEBRATA. 
Mollusca. 


Digestion of Amyloids in Cephalopoda.t—E. Bourquelot in 
attempting to resolve the contradictory statements that have been 
made with regard to the presence of a diastatic ferment in the liver of 
the Cephalopoda, finds that the quantity of starch which is altered 
varies with the condition of the individual. When it is starving the 
action is slow and difficult to detect, for the gland is then in repose; but 
when digestion is going on in the animal the change is almost instan- 
taneous. As in mammals, ruptured starch-grains are alone acted on. 
It is somewhat curious, the author thinks, to find this ferment in car- 
nivorous animals, but its presence affects the discovery of the possible 
glycogenic function of the Cephalopod’s liyer. Can glycogen and 
starch-ferments exist in the same gland? as yet there is no proof of 
the presence of sugar in livers that have been properly treated, but, as 

_the author justly remarks, in physiological chemistry an experiment 
yielding negative results should be frequently and carefully repeated. 
* Comptes Rendus, xciii. (1881) pp. 854-6. 


+ See this Journal, i. (1881) p. 874. 
t Comptes Rendus, xciii. (1881) pp. 979-80. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. ok 


Proneomenia sluiteri.*—Dr. A. A. W. Hubrecht gives a full 
anatomical account of this interesting archaic Mollusc, the discovery 
of which we have already noted.t There are no external appendages ; 
the groove enclosing the foot is indicated by a dark longitudinal 
line, the mouth and anus are at either extremity. The integument 
is stiff owing to the presence of several layers of spicules of 
carbonate of lime; externally to the circular layer there is a cellular 
one, which appears to be the matrix of the integument; and 
there is an interspicular substance which is homogeneous and 
structureless, and appears to be of a chitinous nature. The youngest 
spicules are found quite close to the deep cellular layer of the 
matrix; the older ones are in communication with this layer 
by radiating cords of connective tissue, and the points of the inner- 
most project towards the exterior. So far there are certain im- 
portant differences between this form and Neomenia, and, in the 
latter, blood-vessels find their way into the skin; moreover, in 
Proneomenia at the hinder end of the body there are two symmetri- 
cally developed czeca connected with the anal cavity, and containing a 
special secretion; they are provided with a strong muscular invest- 
ment, so that, whatever their homology or functions may be, there 
can be no doubt that at times their contents may be forcibly 
expelled. 

In his account of the muscular system the author states that 
in Proneomenia, as in Neomenia, the stronger muscular fibres are 
enclosed in a delicate sheath of connective tissue, which forms trans- 
verse folds and so gives to the muscle the appearance of being 
striated. The most anterior portion of the ventral groove leads 
into a system of ciliated slits and cavities which ramify and com- 
municate with one another; the whole would seem to form a gland— 
the “anterior foot-gland.” The posterior foot-gland has no ciliated 
cavities. 

The nervous system truly belongs to the type of the Amphineura ; 
the single cephalic ganglion is comparatively very small; it gives off 
three separate pairs of principal trunks, the innermost of which forms, 
asin Chiton, a sublingual commissure ; the second pair surrounds the 
pharynx and developes the anterior pedal ganglia; the third pair 
gives rise to the longitudinal lateral nerves, and “a regular series 
of commissures similar to those between the two pedal nerves, 
connect the two lateral with the two pedal nerves.’ The study of 
the details of the nervous system reminds Dr. Hubrecht that all late 
investigations into the lower Invertebrates appear to point towards 
an increased complication of the commissural connections, culminating 
in the direct continuity of nervous tissue throughout more or less 
extensive regions of the body. It is remarkable further, that “the 
lower we descend in the Molluscan subdivision the more a system of 
transverse commissures between the longitudinal connective stems 
fixes our attention.” Perhaps, indeed, the earlier Mollusca had their 
nervous system plexiform in arrangement. Further, the fact is of 


* Niederl. Arch. f. Zool., Suppl. Band I., ii, (1881) 75 pp. (4 pls.). 
t See this Journal, i. (1881) p. 28. 


32 SUMMARY OF OURRENT RESEARCHES RELATING TO 


importance that the primary nerves are accompanied by a layer of 
nerve-cells.* 

The digestive system is divisible into a muscular buccal mass, a 
ciliated intestine and the rectum; the pharynx possesses a number of 
radial folds, and there is an inner coating of a yellowish chitinous 
cuticle. No trace of a radula is to be seen in Neomenia, but in Proneo- 
menia it is interesting to observe a muscular process representing the 
tongue and invested in chitin; salivary glands appear to be present. 
The intestine is uniform throughout, with thin walls, provided 
anteriorly with a cecum; the lumen is obstructed by the deep trans- 
verse folds, found in this form and its allies, and there are indica- 
tions of an incompletely differentiated liver, in the form of secreting 
cells on the lateral portions of these lamine. 

The generative system is perfectly symmetrical, and consists of the 
germ-gland, which is situated along the whole length of the body, 
and is dorsal, and of the different cavities and canals found at the 
hinder end of the body. The general type in the Solenogastres 
appears to be the possession of a double genital gland which com- 
municates with the pericardium ; from this a complex of ciliated and 
glandular ducts leads towards the exterior, to which it opens in the 
region of the anus. The author thinks it possible that part of the 
conducting tubes of the genital system represent the kidney. If this 
view is supported, we shall find in Neomenia a form in which 
the genital products are discharged by a pair of ducts into the 
body-cavity (pericardium); thence they are conducted by paired 
ciliated ducts into the cavity of the kidney; in other words, we 
have indications of a more primitive stage in which the cavity of the 
pericardium was the meeting-point of the efferent ducts of the genital 
glands, and the excretory ducts of the renal organ. 

The circulatory system is almost completely lacunar, the heart is 


more or less saccular in form, and as radiating fibres traverse its — 


cavity, it has a resemblance to the embryonic heart of some higher 
Gastropods: it is possibie that the blood-corpuscles contain hemo- 
globin. There appear to be no branchie at the posterior extremity 
of the body. The paper concludes with a detailed comparison of this 
form with Neomenia and Chetoderma; and of the Solenogastres 
generally with the other division of the Amphineura—the Polypla- 
cophora. 
Molluscoida. 

Development of Salpa.t— Professor W. Salensky has a preliminary 
communication on this subject, to which his attention has been 
compelled by the different results obtained by Brooks and Todaro, 
as compared with those of his own earlier investigations. He now 
finds that there are great differences between the S. democratica which 
he previously examined, and the S. pinnata, which was the subject of 
Todaro’s studies. In all species of Salpa the ovary is found at the 
hinder end of the body, and consists of an egg-cell, enclosed in a 


* We may observe that Balfour has noted a number of commissures between 
the ganglia, and a ventral ganglionic layer in the ventral cords of Peripatus. 
t Zool, Anzeig., iv. (1881) pp. 597-603, 613-19. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. oa 


follicular capsule ; this follicle has a solid stalk, which leads into the 
oviduct; where the wall of the respiratory cavity is connected with 
this, it is thickened, and the projection so formed was taken by 
Todaro for the uterus; the maturation of the ovum is always 
accompanied by the shortening of the stalk, till the follicular cavity 
becomes connected with the oviduct. After this impregnation takes 
lace. 

* In further development differences obtain between’ the species as 
to the form of the embryo, of its coverings, and of the number of 
follicular cells. Considerable differences are seen early between 
S. democratica and S. bicaudata ; the former has no amniotic fold, the 
latter lies in a prolongation of the body, formed from the cellulose- 
mantle, blood sinuses, and a tubular continuation of the wall of the 
respiratory cavity. The first signs of the differentiation of the 
- central mass is the separation of the lower wall of the follicle, and a 
cavity is thus formed which the author proposes to call the follicular 
cavity, instead of applying Todaro’s unsuitable term of cleavage- 
cavity; this wall becomes the upper wall of the placenta. In 
S. pinnata the nervous system arises in the form of a tube with an 
at first narrow lumen. In the other species the ganglion has the 
form of an aggregate of cells, derived from the follicular cells. 
From the connecting canal between the enteric and neural cavities 
we have formed a ciliated pit. An account is given of the 
formation of a special organ known as the subpericardial aggregate 
of cells; Uljanin has informed the author that a similar structure is 
to be observed in Doliolum. The eleoblast is formed from the 
amceboid follicular cells which give rise to the blood-corpuscles and 
muscles. 

The author insists on the great differences between the develop- 
mental history of Salpe and that of other animals, the organs being 
formed not from the cleavage, but from the follicular cells; some- 
thing similar has, however, been noted in the allied Pyrosoma; and, 
instead of speaking of development of Salpe, he would prefer to give 
the process the name of follicular gemmation. 


Tunicata of the ‘Challenger.’ *—JIn a fourth communication 
Dr. W. A. Herdmann deals with the Molgulidew, and describes 
Molgula pedunculata, horrida, forbest, and pyriformis, Hugyra kergue- 
lenensis ; Ascopera is a new genus with a pyriform, more or less 
pedunculated body, the test thin, while the branchial sac has seven 
folds on either side: A. gigantea and A. pedunculata. 


Arthropoda. 
a, Insecta. 

Striated Muscle of Coleoptera and its Nerve-endings,|—The 
main results obtained by Professor L. v. Thanhoffer on this subject 
show the striated muscle of Coleoptera to possess two separate sarco- 
lemmar membranes, between which the nerye-ending plate spreads 


* Proc. Roy. Soc. Edinb., 1881, pp. 233-40. 
+ Biolog. Centralblatt, i. (1881) pp. 349-51. 


Ser. 2.—Vot. II. D 


34 SUMMARY OF CURRENT RESEARCHES RELATING TO 


out, the axis-cylinder of the nerve dividing dichotomously, and the 
nerye forming a reticulum in the plate. In the Frog no such 
reticulation is formed, but the divisions of the axis-cylinder come 
into contact with the nuclei which overlie the muscle-fibre. In the 
beetle the nerve-substance of the plate is separated from the muscular 
substance by a membranous structure which is connected with 
Krause’s transverse lines. Strong contraction, produced by electricity, 
causes resolution of the transverse lines of the muscle into molecules ; 
but fine strie, due to the approximation of Krause’s lines, are still to 
be seen, except after very violent contraction, All the described 
forms of cross lines can be seen in the Coleopteran muscle. The 
outer sarcolemmar sheath is in connection with the outer sheath of 
the tendon; areticular lymphatic canal-system ramifies from the latter 
and terminates in the uniting substance of the fibrils, showing cell- 
like granular structures at the points of division. 

These canals show connective-tissue cells bearing processes shaped 
like windmill-sails at the point of insertion of the tendon. The main 
nerves of the muscles lie in special “ perineural ” cavities, lined with 
amultilaminar sheath. Isolated muscular fibres of Hydrophilus piceus, 
connected with end-plates, show the Krause’s lines next to the mem- 
braneous neural septum to be in close apposition, whereas towards 
the sides they become gradually more distant ; they appear to converge 
towards the plate when near it, but to diverge when remote from it. 


Terminations of the Motor Nerves in the Striated Muscles of 
Insects.*—H. Viallanes has studied the mode of termination of the 
nerves in the muscles of the larve of Stratiomys chameleon Macq. and 
Tipula gigantea Macq., and finds that in both the muscular fibre is on 
the same plan as that of Vertebrata ; and consequently differs greatly 
from that of adult insects, which is histologically distinct. The 
results which he obtained cannot therefore be compared with those 
obtained by most of his precursors, who studied chiefly adult insects. 

In Tipula each muscular fibre receives only a single nerve, and 
has only one Doyére cone: but in Stratiomys each receives several 
nerves, and has several Doyére cones. 

The sheath of the nerve continuous with the sarcolemma constitutes 
the wall of the Doyére cone. 

The axis-cylinder haying penetrated to the summit of the cone 
divides into two principal branches, which give off secondary branches; 
these again divide dichotomously a great number of times. There 
results a terminal nervous plexus beneath the sarcolemma, and com- 
parable to that in the Vertebrata. The author claims to have been 
the first to point out such a plexus in other animals than Vertebrata. 

This plexus occupies a considerable area in Tipula; but is much 
reduced in Stratiomys. 

As in the Vertebrata, all the branches of the plexus are situated 
between the sarcolemma and the contractile mass; they seem to 
terminate in a slender point as in the frog. 

Special nuclei are adherent to the branches of the plexus, and 


* «These pour le Doctorat en Medicine,’ 8vo, Paris, 1881 (45 pp. and 3 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 30 


accompany them throughout their course. These the author calls 
“ nuclei of the plexus” (noyaua de Tarborisation), comparing them to 
those so named in the Vertebrata. 

In Tipula there is attached to the principal branches of the plexus 
a granular substance provided with special nuclei, which must be 
compared to the “ fundamental nuclei” and “ granular substances” of 
the plexus of the higher Vertebrata. They are completely wanting 
in Stratiomys. 

Between the plexus of Stratiomys and Tipula there exists a differ- 
ence analogous to that observable between the plexus of the frog and 
that of the lizard. 

These results do not necessarily invalidate, the author says, those 
of Ranvier and Foettinger, because he has dealt with a histologically 
different matter. They confirm, however, the observations of Rouget, 

-who has described the axis-cylinder as forking in the interior of the 
cone, the two branches of the fork being applied to the surface of the 
contractile mass but not appearing to extend further. They also 
confirm his view that the granular matter which fills the cone is of 
little importance, being absent in Sératiomys. 


Wings of Insects.*—Dr. G. E. Adolph figures a large number 
of wings chiefly of Hymenoptera, and points out that the arrange- 
ment of the concave and convex lines is the most constant character, 
but that the concave are much more persistent than the convex. A 
study of the arrangements seen in Vanessa has shown him that the 
tracheal system of the wing is first developed along certain primary 
lines, the most primitive and striking peculiarity of which is their 
tracheal nature; between these there are developed certain costal 
elements. After dealing with the Lepidoptera he passes to the 
Diptera, and in their case, as in that of the Neuroptera, he institutes a 
comparison with the Hymenoptera, pointing out how fresh branches 
become developed and earlier nervules absorbed. 

In a second paper { he deals with certain abnormal developments 
in the wings of some Hymenoptera. 


Structure of the Proboscis of Lepidoptera.t—W. Breitenbach, 
dealing with the phylogeny of this organ, finds in the early stages of 
the insect indications of its origin, for in the late larva it has been 
found already represented by two long curved cords. But further, the 
obvious connections of the group with the Trichoptera show that the 
biting mouth of the latter has produced the sucking tube of the former 
by modification of the labium, maxille, and labrum, which were at 
first all united into a tubular organ; the edges of the two maxille 
then became more closely approximated, and the share of the other 
two parts in the organ became unnecessary, and they were excluded 
from it. This metamorphosis, however, was probably made in various 
stages, each having some definite advantage to the insect as its object: 
e.g. the exclusion of the labrum and labium from the organ was a 


ty é Nova Acta Acad. Ces, Leop.-Carol. Germ. Nat. Cur., xli. ii. (1880) pp. 213- 
6 pls.). 

+ Tom. cit. pp. 293-328 (1 pl.). 

¢ Jenaisch. Zeitschr. Nat., xv. (1881) pp. 151-214 (3 pls.). 


36 SUMMARY OF CURRENT RESEARCHES RELATING TO 


beneficial simplification, the great object being to bring the two 
maxille together; the latter organs were able to assume a greater 
development in consequence of the reduction of the former; this 
development was further promoted by the abnormal method by which 
food was obtained. The increase in the length of the tube was caused by 
the depth which the nectaries of certain flowers exhibited, and by which 
they excluded insects hurtful to them, while, at the same time, this 
very depth allowed of the accumulation of a greater amount of honey. 

The transverse striation of the tube, noticed by Réaumur, is 
produced by semilunar bands of chitin, which are set side by side 
from the root to the extremity of each half-tube in two series of 
half-hoops, exterior and interior; the degree of their development 
varies in different insects; they are most slender at the apex, a fact 
which is partly due to the space occupied by certain papilloid pro- 
cesses on this part. The form of the bands also varies; in some 
Lepidoptera they are broken up into a series of separate chitinous 
pieces; sometimes, as Gerstfeldt has observed, they are forked, but 
in this case they are divided only into two arms, not three, as stated 
by that observer. The transition from the condition in which the 
bands are composed of series of separate pieces to that in which 
they form continuous strips is well seen in passing from Pieris to 
Vanessa, though even in the latter genus (e.g. V. cardui) the trans- 
verse chitinous series are not wholly united into bands. It is un- 
certain whether the disconnected or the consolidated form of the 
chitinous bands of the tube is the primitive condition. The apposed 
edges of the two halves of the tube may be either serrate (Egybolia) 
or plain (Argynnis). 

The apex of the proboscis presents, as already well known, certain 
organs called juice-borers. The simplest form of these is (1) that of 
simple hairs, which occur on every proboscis, and consist of a basal 
chitinous ring, the “cylinder,” and a true hair-shaft, which is 
traversed by a horny mass, the “axial radius,” termed “central mass” 
in the juice-borers; the cylinder is usually imbedded in the main 
substance of the tube. When true sap-borers coexist with them, the 
hairs are short, and vice versd. The varieties in form of the juice- 
borers are caused by varieties in the peripheral portion of the shaft. 
2. Juice-borers, with the upper edge of cylinder dentate, e. g. Vanessa. 
Cylindrical or barrel-shaped, the teeth are six to eight in number, 
moderately sharp; in Pyrameis virginiensis they are cylindrical, 
laterally compressed. 3. Juice-borers with longitudinal ridges formed 
by the chitinous covering of the “central mass” which spreads out 
into six plates, running parallel to its axis, e. g. Catocala, Noctua, 
Plusia, Mamestra, Agrotis, Triphena, Phlogophora, ‘Tceniocampa, 
Euclidia, &e. 4. Juice-borers of <Arge Galathea. Upper surface 
armed with six teeth, and three similar whorls of teeth in succession 
below them, parallel to the first series; the points are directed towards 
the apex of the organ. 5. Unarmed juice-borers; e. g. those of 
Argynnis, Melitea, Ageronia Arete, Macroglossa, Hesperia, Taygetis 
Xanthippe, Heliconius, Eneides, Agraulis, &c. 6. Juice-borers of 
Scoliopteryx libatrix. Of two forms. (a) A thick-walled cylinder, 


re 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 37 


the edge armed with two blunt processes, the point of the central 
mass projecting between them, and armed with chitin. (6b) as (a) 
but the point of the central mass prolonged to as great a length 
as the cylinder itself, or greater. 7. Hgybolia Vaillantina. A very 
thick-walled cylinder, the central mass projecting by a small conical 
process from its extremity. A form allied to this is exhibited by 
an Australian moth, viz. a pointed cylinder, the central mass pro- 
jecting from its side as a very small process. 8. Recurvate juice- 
borers. Recurvate hooks, calculated to lacerate the tissues when the 
proboscis is withdrawn from a soft vegetable mass into which it has 
been plunged ; e. g. Ophideres, Achwa chameleon, Egybolia Vaillantina, 
Scoliopteryx libatria. 

Functions of Juice-borers.—The object of obtaining supplies of 
juice is clearly that of the last form; that of the simplest forms 
- must be sought in their origin from simple hairs, which must have 
been originally organs of touch ; but, in spite of Fritz Miiller’s view 
as to the general prevalence of this latter function, they must be 
considered, from their structure and position, to be truly and solely 
instruments for extracting juices. The cases in which the structure 
of these organs is known are too few at present to base classificatory 
systems upon them, and in some cases they appear to be little adapted 
for such a purpose, as, for example, the form with longitudinal ridges 
(No. 3), which occurs in numerous European genera of each of the 
three groups, Bombyces, Noctue, and Geometre, besides some genera 
of uncertain position. In the Micro-lepidoptera they have not been 
examined. 

Internal structures of the halves of the proboscis.—The muscles 
consist of a main longitudinal band passing from base to apex, and of 
numerous small branches passing off obliquely from it, and attached 
on the upper side; the latter cause the tube to roll up by contracting 
first near its apex, and then in succession towards the base. The 
nerves are not known. A tracheal tube traverses each of the maxilla, 
ending blindly at its apex. 

The closing of the two halves, in a species of Sphinx, is effected by 
two different arrangements. The lower edges are joined by means 
of a pair of teeth in each half (as seen in transverse section), which 
interlock with those of the opposite half; on the upper side the 
integrity of the tube is effected by fine hairs and spines in the 
two halves, which cross and form a kind of joint. Similar arrange- 
ments appear to occur in some other forms. The act of sucking 
appears to be caused, not by exhaustion of air by means of the 
trachez, as would be the case if the method had an analogy with that 
of higher animals, but by partial separation of the two halves of the 
tube, causing attenuation of the enclosed air, and forming an imperfect 
vacuum, which thus allows the pressure of the external air to act on 
the juices of the flowers attacked by the insect. 


Post-embryonic Development of Diptera.*—H. Viallanes, noting 
that of all insects the Muscide exhibit the greatest differences between 


* Comptes Rendus, xciii. (1881) pp. 800-2. 


38 SUMMARY OF CURRENT RESEARCHES RELATING TO 


the larval and the perfect state, has continued the investigations of 
earlier naturalists by a study of Musca vomitoria. When the larva 
becomes converted into the pupa, the skin of the whole of the body, and 
not only that of the head and thorax, undergoes degeneration of the 
hypodermic cells; and this is carried so far, that at one time the 
animal has nothing but a delicate cuticle covering it ; the embryonic 
cells which fill nearly the whole of the body of a pupa are not all 
derived from the nuclei of the muscle-cells, some are formed by the 
proliferation of the cells of the fat-body. It is pointed out that the 
return of the tissues to the embryonic condition is the cause of the 
pupa having, at a certain time, really the characters of an embryo; 
if we make a section across the abdomen of a pupa between the second 
and fourth days we see that it is only composed of two layers of 
central cells, one formed from the epithelial cells of the digestive 
tube and the other, set peripherally, and formed by embryonic cells 
derived from the muscular nuclei and the cells of the fat-body. The 
imaginal disks seem at first to form a hollow sphere in which one 
part has been pushed into the other; the inner layer is thick, and 
made up of pyriform cells, the outer layer is delicate, and its cells 
flattened. Later on, the latter disappear, and the inner layer gives 
rise to the integument of the adult. The disks for the eyes are 
distinguished by having the cells of their inner layer regularly set 
side by side; they are cylindrical in form, and their inner extremity 
is pointed; by this they become connected with the fibrils of the 
optic nerve. The author finds that the integument of the abdominal 
region of the adult is formed by the conversion of the embryonic into 
hypodermic cells, the hypoderm first appearing, for each joint, at two 
superior and two inferior points. Further observations are promised 
which will deal with the metamorphoses of the nervous system. 

Criticizing the statements put forward by Viallanes, Kiinckel* 
points out how the author’s view, that the embryonic cells are partly 
formed by proliferation of cells of the fat-body, has been contradicted 
by his own observations and those of Ganin, which show this body 
to be no more than a reserve of nourishment, in other words, a 
post-embryonal vitellus. The buds which give rise to the integument 
of the head and thorax have been wrongly termed “histoblasts” by 
Viallanes, for they have not, as the term would imply, a common 
origin and common constitution, but give rise to the nerves, trachex, 
and the skin itself; their structure has been rightly elucidated by 
Ganin as that of small sacs filled with cells, and as having an exoderm 
and mesoderm. The development of the hypodermic cells, as 
already described by Ganin, is essentially the same as that described 
by Viallanes. 

A justification by Viallanes of his statements is given in a sub- 
sequent paper,t in which he points out that Ganin regarded the 
hypodermis of the abdomen of the adult as being developed by trans- 
formation, while he has proved that there is a true degeneration of 
the cells. 


* Comptes Rendus, xciii. (1881) pp. 901-3. 
+ Loe. cit. pp. 977-8. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 39 


Development of Adoxus vitis.*—M. Jobert has been studying the 
generation of this, next to Phylloxera, most dangerous enemy of 
viticulture. A smaller and a larger form are to be distinguished, but 
dissection shows that they are both females. A little above the point 
where the ovary joins the oviduct, a spermatheca opens by a duct; 
it forms a well-developed glandular organ without any copulatory 
pouch. Two long tubular glands also open into the vagina. The 
idea arises that the males died before the females came out, or that 
they do not resemble the females; however, the author was on no 
occasion able to detect the presence of spermatozoa in the copulatory 
pouch. One hundred insects were collected, of which 50 were dis- 
sected and found to be unimpregnated females; the others were kept 
alive and isolated. After some time they laid each from 25 to 30 
eggs; two were immediately killed, and still found to be without 
spermatozoa. The eggs that were laid were fertile. 

As against the theory of parthenogenesis we have to note the 
possibility of hermaphroditism, for at the moment of ovipositicn the 
tubular glands are well developed, and contain a mass of a refractive 
substance, which, when highly magnified, resolved itself into a 
prodigious quantity of vibratile rods, one-hundredth of a millimetre 
long. 

Colouring Matter from the Willow-tree Aphis.j—Mr. C. J. 
Muller finds that the abdomen of Lachnus viminalis—an Aphis which 
feeds on the juices of the bark of the willow-tree—is filled with hard 
granules, like grains of sand variously coloured, green, red, and 
yellow. A gentle heat fuses them, and the fused mass on cooling 
exhibits under the polariscope all the characteristics of salicine. 
This is best seen by digesting the insects in pure benzole, the deep red 
solution then obtained being afterwards evaporated on a glass slide. 
The author considers that the colouring matter belongs entirely to 
the juices of the tree on which the insect feeds, and that it is not in any 
way manufactured by the Aphis (except in so far as animal heat and 
the digestive process may influence it), so that if this opinion is 
correct, it would account for Dr. Sorby not finding in the red Apple 
Aphis the physical and optical properties of the colouring matter of 
the Cochineal insect. The latter feeding upon a plant altogether 
different from the apple, the character of its colouring matter will 
necessarily differ. 


y. Arachnida, 


Liver of Spiders.t—Dr. P. Bertkau states that the gland which 
has been so called, lies in the hinder part of the body, where it is 
divided by the heart and intestine into two halves; in most species it 
completely invests the generative organs and spinning vessels. The 
gland is follicular in structure, the separate follicles being united 
into larger masses by the tunica propria. The cells are large and 
cylindrical, and they contain a quantity of large and smaller spheres, 


* Comptes Rendus, xciii. (1881) pp. 975-7. 
+ Proc. Eastbourne Nat. Hist. Soc., 18th Nov., 1881 (6 pp.). 
t Zool. Anzeig., iv. (1881) pp. 543-4. 


40 SUMMARY OF CURRENT RESEARCHES RELATING TO 


the former of which lie near the lumen and the latter near the wall 
of the gland. Between the separate follicles we find a connective 
tissue with the characters of fat-cells and traversed by renal canali- 
culi. The secretion of the gland is neutral or faintly acid; on being 
dried and heated with fibrin it gave its distinct peptine reaction, which 
was most marked in alkaline solutions; it appears to possess both a 
tryptic and a peptic ferment. 


Limulus an Arachnid.*—Professor E. Ray Lankester examines 
part for part the apparently corresponding structures of Limulus (the 
King-crab) and a Scorpion, Commencing with the nervous system, an 
exact knowledge of which in the latter is still a desideratum, he points 
out that in Limulus we have (a) an archi-cerebrum whence five nerves 
only are given off; (b) an cesophageal collar whence nerves radiate to 
all the pediform gnathites, as well as to the chilaria and the genital 
operculum, there being a distinct nerve for each appendage; (c) the 
first half of the abdominal cord gives off no nerves, the latter five pairs. 
Precisely corresponding portions may be made out in Scorpio, where, 
however, the brain and the cesophageal collar are more intimately 
fused ; Newport’s figure shows that the nerves “have a lateral position 
embracing the true archi-cerebrum.” What Professor Lankester calls 
the attraction of nerve-organs to the cesophageal collar has gone further 
in Scorpio than in Limulus, for the nerves for the segments contain- 
ing the first two pairs of lung-books likewise arise from the collar 
itself. 

The striking resemblances between the skeletons of the two forms 
are next illustrated, and it is pointed out that the so-called compound 
eyes of Limulus are more correctly regarded as aggregations of simple 
eyes; the differences between the abdominal regions are diminished 
when we remember that the embryonic Limulus has a series of separate 
segments in this region, the presence of which is still denoted by a 
series of ridges and by the lateral spines, each of which would appear 
to possess its separate musculature, as well as by the dorsal pits or 
“entapophyses.” Between this and the anus, Limulus has an area 
which is only potentially segmental, and behind these comes in both 
a telsonic spine. Behind the six cephalothoracic appendages there is 
the genital operculum, a lid-like plate which in Limulus retains 
throughout life indications of its double origin, but in Scorpio is only 
bifid at its free margin. As is well known, the 8th pair of the 
appendages in the Scorpion are the pectines; in the King-crab, the 
pieces on either side become united across the middle line, but on 
their under surface there is still to be seen “a series of very delicate 
lamelle, corresponding to the lamelliform teeth of the Scorpion’s 
comb-like appendages. Precisely similar pieces are found on the 
9th-12th appendages of Limulus, but in the Scorpion the rudimentary 
appendages have disappeared,” but only from view—in other words, 
the lamelligerous appendages of these four segments sink within the 
lung-invaginations. When a close examination of the sternal area of 
this region of Limulus is made stigmata are found which lead into 


* Quart. Journ, Micr. Sci., xxi. (1881) pp. 504-48 (2 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 41 


pits; these parabranchial stigmata are found on the posterior face of 
the median sternal lobe which unites the two halves of the lamel- 
ligerous appendage ; they are connected with powerful muscles, the 
function of which is clearly to agitate the plate-like organ, for the 
purposes of respiration. A still more intimate knowledge of the struc- 
ture of the lamelligerous appendages in the two forms reveals their 
essential similarity in structure; an axis springing from the body- 
wall has its posterior face provided with a transverse series of lamelle ; 
when these are all set in a corresponding position we find that they 
are always imbricated, and that the imbrication is identical in all, and 
that they only present such differences, as density of structure, &c., as 
are to be explained by a reference to their different positions and 
functions. The history of these structures is next hypothetically 
detailed, and it is pointed out that in living Scorpions the original 
stigma has closed up and that a new opening (the stigmatic slit) has 
been developed within the area formed by the closure of the stigma ; 
and air now enters where before there was blood. 

The characters of the free entosternite in the two forms are then 
described and compared; and it is stated that in no Crustacean are 
such developments to be observed. The alimentary tract is similarly 
treated, and the fact that the proctodceum is so short in Limulus is 
stated to be one of the most important points of difference ; but this 
itself is only a part “of that general reduction of its hinder seg- 
ments”; another difference is the absence of Malpighian glands in 
the King-crab. This portion of the paper concludes with an account 
of the circulatory and generative organs. 

The Hurypterina present numerous well-marked indications of 
forming a link between the two forms here compared together. After 
a review of the opinions held by preceding writers, Professor Lankester 
proceeds to the development in time of Limulus and the Tracheate 
Arthropoda; from the latter he would separate the Arachnida as 
not having any special connection with the Hexapoda and Myria- 
poda, the exact relations of which to the other Arthropods is still a 
matter for speculation. The Arachnida may be divided into three 
orders: Hematobranchia (= Merostomata), Aerobranchia (Scorpions 
and Spiders), and Lipobranchia (Mites, Pseudoscorpions, &c.). 


Function of the Caudal Spine of Limulus.*—J. de Bellesme, 
after pointing out that this organ cannot, on account of the mode of 
disposition of the spinules on its lower surface, act as an organ of 
offence, the need of which, for such a creature, can hardly be ima- 
gined, states that the appendage may move vertically through 80°, 
and that it has a great power of lateral movement. When a King- 
crab falls on its back, it flexes its prothorax and the tip of the spine 
touches the ground; the creature now rests on only two points ; easily 
enough it sways to one side or the other till one edge of the carapace 
touches the ground; all that it then has to do is to alter its centre of 
gravity by moving its limbs, and it will be found to veritably fall on 
its feet. 


* Ann. Sci. Nat. (Zool.), xi. (1881) art. No. 7, 5 pp. 


42 SUMMARY OF CURRENT RESEARCHES RELATING TO 


5. Crustacea. 

Adaptations of Limbs in Atyoida Potimirim.*—This Brazilian 
fresh-water shrimp to which Dr. Fritz Miiller has already + drawn 
attention in connection with its coloration, is now described on 
account of the peculiar structure of its first thoracic leg and some 
other of its appendages. Instead of being constructed, as in the 
immediate allies of Atyotda,{ to cleanse the branchial cavity, the 
appendage mentioned acts as a kind of spoon to provide the mouth 
with supplies of the fine mud on which this species lives. Whereas 
in the nearly allied genus Palemon, the “ hand” (propodite) is long, 
and provided with a grasping apparatus in the form of a long slender 
thumb and movable finger (dactylopodite), in Atyoida, the proximal 
portion of the hand is almost aborted, the finger being articulated to 
the thumb itself almost in the joint between the hand and carpopodite. 
The end of each of these parts is provided with a tuft of long bristles, 
which, when the hand is open, form a kind of fan which detains the 
fine mud; when the hand is closed the bristles are closed around the 
mud, compressing it into a pellet, which is passed into the mouth 
with great rapidity ; the same takes place with the three following 
maxillipedes. Further, the posterior maxille, the first and the 
middle maxillipedes, have each an unusually long and straight inner 
edge, fringed with bristles of peculiar form, and, in conjunction, 
forming an organ admirably adapted for receiving the pellets of mud 
brought in by the legs. The mandibles form a remarkable exception 


to the rule in the order, in being unsymmetrically developed, a con-. 


dition which appears to be rather due to preservation of an ancestral 
character than acquired by adaptation, as the jaws in their earlier 
stages resemble those of the Cumacea and Amphipoda. 

The 3rd, 4th, and 5th maxillipedes bear the usual appliances for 
grasping water-plants; but the lower edge of the dactylopodite of 
the 5th pair is provided with a comb-like appendage for cleansing the 
abdomen; for this purpose the abdominal appendages are successively 
bent forward and subjected to its operation, and finally the tail itself. 
The branchial chamber is cleaned by the 2nd pair of maxille, the 
outer part of which is usually known as the scaphognathite ; its 
epipodite portion, instead of being short and broad, is long and 
narrow, tapers to a point, and carries a dozen long flexible bristles, 
and is thus able to reach as far into the chamber as the gill of the 3rd 
ambulatory leg, and to reach with its bristles to the very extremity 
of the chamber, and thus to traverse all the surface of the branchie. 

Another contrivance serving the same purpose, is the set of small 
sausage-shaped processes which spring from near the anterior edges 
of the coxopodites of the posterior maxillipedes, and the three 
anterior ambulatory legs; each process carries about a dozen long 
hairs and lies back over the coxopodites, and being placed in the 
entrance to the gill-chamber, hinders, in conjunction with its fellows, 
the admission of foreign objects. The want of a similar provision in 

* Kosmos, viii. (1881) pp. 117-24 (20 woodcuts). 


+ Cf. this Journal, i. (1881) p. 452. 
t See this Journal, iii. (1880) p. 63. 


mers 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 43 


the case of the 4th and 5th pairs of legs, is supplied by the remark- 
able forward projection of the exopodite of the Ist pair of abdominal 
legs, which plays in front of the space between the last ambulatory 
leg and the carapace. 

As in the case of other shrimps in which the male is not provided 
with offensive weapons, that sex is smaller than the female ; its chelx 
are adapted only for prehension of mud; the only appliances by 
which the female is grasped in copulation are a bent claw on the last 
maxillipede, and a strong toothed hook on the inner aspect of the 
tarsi of the 8rd and 4th legs. The spina pterygostomiana of the lower 
edge of the front of the carapace, which has been used as a generic 
character in Leander, is here present only~in the adult female; it is 
thus here merely a sexual distinction; the young females agree, 
however, with the males in this, and also, owing apparently to their 
similar proportions, in the number of bristles on the telson. 

These numerous peculiarities in the structure of <Atyoida dis- 
tinguish it from its allies, Palemon, Hippolyte, &c., in the same way 
as not one but several peculiarities usually separate other species and 
genera, and also families from each other. The connection between 
the peculiarities in this case lies in the peculiar mode of life, viz. the 
use of mud as food-material, and the habit of clinging to plants; 
which has caused the modification in such an extraordinary manner 
of the parts concerned in, or affected by these functions. 


Colour-sense in Crustacea.*—C. Mereschkowsky has experimented 
with the view of determining whether the lower Crustaceans distinguish 
colours. 

Larve of the Cirrhipede Balanus and some marine Copepoda, 
enclosed in a vessel, seemed fully alive to the difference between 
light of any kind and darkness; for whereas, in the dark, they were 
scattered throughout the vessel, they always gathered about a ray of 
any light coming from a slit. The author considers, however, that it 
is exclusively the quantity of light, not the quality, that affects them. 
Using two slits, one to admit white light, the other coloured, he 
found that they preferred the former—all gathering round it if the 
coloured light was deep red or violet, and most of them if the colour 
was bright red, yellow, or green. They always preferred a bright 
light like yellow to a sombre one like violet. When two rays of 
equal intensity were admitted they gathered in nearly equal numbers 
about them, whatever the nature of the colours. There is, then, a 
great difference in the mode of perception of light, between the lower 
Crustaceans and man, and even between them and ants. While we 
see different colours and their different intensities, the Crustaceans see 
only one colour with different variations of intensity. We perceive 
colours as colours; they only perceive them as light. 

Germs of Artemia salina.tj— A. Certes has a note on the 
vitality of the germs of this species and Blepharisma lateritia. He 
states that having evaporated some water and collected carefully the 
sediment, he three years afterwards heated the residue with boiled 


* Comptes Rendus, xciii. (1881) pp. 1160-1. + Ibid., pp. 750-2. 


44 SUMMARY OF CURRENT RESEARCHES RELATING TO 


and filtered rain-water. On the following day, and notwithstanding 
that all care had been taken to keep out germs from the air, Flagellata 
exhibited themselves; soon afterwards there came Ciliata; about two 
months later Nauplius-like germs were detected, the number of which 
rapidly increased, and later on they took on the form of Artemia 
salina. The author points out that, in cases of this kind, death has 
only been apparent ; organic combustion and nutritive changes have 
not ceased entirely. 

A somewhat similar account is given of the rare rose-coloured 
Infusorian Blepharisma. 


Vermes. 


Origin of the Central Nervous System of the Annelida.*— 
Prof. N. Kleinenberg gives a summary of the results obtained by him 
in studying the development of the Polycheta, upon which he proposes 
hereafter to publish a more extended memoir with figures. At present 
he confines himself to making known the development of a single 
species, the larva of Lopadorhynchus, until its transformation into the 
perfect animal. 

The most interesting point in the present communication is the 
discovery of the circular nerve of the yibratile organ of the larva, and 
the investigation of the development of the central nervous system of 
the perfect animal. The author has found that during the trans- 
formation of the larva into the perfect animal the circular nerve dis- 
appears completely, together with the vibratile organ; and the 
rudiments of the typical central organs are not derived from the 
transformation of the circular nerve, but originate from other parts of 
the ectoderm. Consequently the nervous system of an Annelid is 
not homologous with that of its larva. He thinks that the larve of 
the Annelida possess only the central anterior nervous system of the 
Ceelenterata, but that the perfect animals have central organs proper 
to them; so that “the organ of the inferior type originates and 
functions in the larva, but is eliminated and replaced by new forma- 
tions in the adult animal.” 


Swim-bladder-like Organs in Annelids.j—Dr. H. Eisig states that 
in preserving specimens of Hesione sicula, he has often observed a 
considerable number of air-bubbles escaping from the mouth or anus; 
by this and by the observation that in some cases specimens of the 
same Annelid are found passively floating on the surface of the water 
in which they were placed, he was led to the discovery that two con- 
tractile appendages communicate with the intestine, and that these 
must be regarded as the reservoirs of the gases; according to their 
condition they may appear as inconsiderable diverticula or as distinct 
bladders; he explains the fact of their being overlooked by previous 
observers as due to their ordinarily empty condition after death. On 
examining specimens of Syllis awrantiaca it was found that the so- 
called T-shaped glands of the Syllidea are swim-bladders. 


* Atti R. Accad. Lincei, Transunti, vi. (1881) p. 15. See Ann. and Mag 
Nat. Hist., ix. (1882) p. 67. 


+ MT. Zool. Stat. Neapel, ii. (1881) pp. 255-304 (3 pls.) 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 45 


When a detailed examination is made of H. sicula it is found that 
the enteric tract may be divided into (a) a proboscis with an ceso- 
phagus, (6) the proper digestive gut, and (c) an intermediate fore- 
stomach to which the bladders are attached. The first and last 
portions of the gut (a and 6) differ not only in external appearance, 
but also in structure; while in the former the epithelium is feebly 
developed, in the latter it gives rise to a well-developed mucous 
membrane ; the constituent cells are greatly elongated and are ciliated 
at their free extremity; it is also richly supplied with blood-vessels 
which, as in the clitellum of the Harth-worm and the epithelium of 
the Leech (Lankester), interpenetrate between the cells; this rare and 
remarkable arrangement would appear to be explained by the fact 
that in the Hesione (as in Syllis) the gills are absent. 

The fore-stomach has very thin walls and when contracted is 
hardly of the length of a somite; it is, however, capable of great 
extension ; in its structure it is intermediate between the cesophagus 
and the gut proper ; for, while it resembles the former in the characters 
of its epithelium, it has the musculature of the latter. At its side the 
two bladders open. Till they approach their orifice these bodies have 
a ventral position, they appear to be easily contractile and of great 
extensibility. When full they form saccular reservoirs ; when empty 
cylindrical tubes, which gradually diminish in diameter towards their 
blind end. Their orifices are wide, but there is a means by which food 
is prevented from entering them, and the valvular arrangement is such 
that, the mouth or anus being closed, gas or water enters them where 
the gut contracts, and water or gas passes from them into the gut when 
they contract. In general structure they resemble the fore-stomach, 
of which therefore they may be regarded as diverticula. 

On examining the characters of the blood-vascular system we see a 
dorsal double trunk, a ventral single, and two lateral ones; the two 
former, by numerous anastomoses, carry venous blood to the walls of 
the stomach, whence it passes to the lateral trunks; these are of con- 
siderable size and contract rhythmically and supply the greater part 
of the body by the thirteen arteries which are given off from them to 
as many somites. The ventral and the lateral vessels are also in 
direct connection by several anastomoses, and each artery is likewise 
in communication with the ventral enteric vessel. In other words, 
the greater quantity of blood is brought into connection with the 
intestine. 

Other Hesionids and the Syllidea are then described; after which 
the author passes to a consideration of the function of the swim- 
bladders ; these were never found to contain food or to give rise to 
any secretion ; they contained nothing but a varying amount of clear 
fluid and gases, both of which could be driven into the stomach, or 
vice versd. The fluid is sea-water, taken in from without, and this 
water appears to be taken in for respiratory purposes. As to the 
“air,” experiment first of all showed Dr. Hisig that it was not. atmo- 
spheric air, and the question whether it was secreted in the animal 
itself was examined, after the following considerations; the air- 
bladders are thin-walled, elastic, and without blood-vessels; the gut has 


46 SUMMARY OF CURRENT RESEARCHES RELATING TO 


thick glandular walls and is richly supplied with blood ; it is, then, 
the prime seat of the respiratory processes. As it was impossible to 
examine the small quantity of gas, the question of its real character 
could not be decided by chemical analysis, but the author concludes 
that it is oxygen secreted from the mucous membrane of the stomach ; 
and as the bladders cannot be supposed to have any hydrostatic 
function, he thinks that they are truly reservoirs of oxygen, which can 
be called upon at periods of digestion and so on, when the animal is 
unable to take in a quantity of fresh sea-water to aerate the blood 
which is passing in such quantities through the walls of its stomach. 

As to the morphological significance of these appendages which 
have already been shown to be diverticula of the fore-stomach, we find 
them to be, in all probability, a product of the endoderm. The 
variations in its development which are to be seen among the Syllidea, 
with the general characters of Syllis, and the absence of any special 
enteric vascular system in T'yrrhena, lead to the conclusion that the 
atrophy of the bladders in some of the Syllidea is due to the develop- 
ment of the dermal mode of respiration. In all Annelids in which 
gills are wanting, and these gills are no peculiar developments, an 
enteric mode of respiration would appear to obtain. We may, in 
conclusion, suppose that, in the ancestors of the Fishes of the present 
day enteric respiration existed (as it does to this day in Cobitis); in 
some this mode led to the formation of a reservoir, which under 
hydrostatic influences took on the function of a hydrostatic organ. 
At the present day we see that a fish uses up all the air in its air- 
bladder before it is suffocated, and even that a pulmonate Vertebrate 
uses its lungs, in water, as a hydrostatic organ. 


Development of Polygordius and Saccocirrus.*—W. Repiachoff 
finds that in both these lowly Cheetopods the cleavage of the ova is 
total; that after eight segments have become developed the embryonal 
cells begin to develope one after another; the gastrula is formed by © 
invagination; while the mesoblast of Polygordius appears to be de- 
veloped from the hypoblast, in Saccocirrus “primitive mesodermal 
cells” are to be found within the cleavage cavity. Even during the 
blastula-stage the embryos of Polygordius begin to swim about by 
means of very fine cilia; after the closure of the blastopore the larva 
becomes more vermiform ; the now-closed anterior end remains, how- 
ever, for some time distinctly swollen out. Movable hairs appear at 
scattered points on the surface of the larva, which give to the creature 
something of the appearance of a larva of Sagitia ; later on, two cirri 
become developed at the anterior end, but this species of Polygordius 
(P. flavocapitatus) never passes through the stage of the Lovenian 
larva. 


Termination of Nerves in the Voluntary Muscles of the 
Leech.j—A. Hansen states that the nerves divide and subdivide 
without forming anastomoses, and lose themselves in the muscles 
without our being able to discover their terminations ; in only one 


* Zool, Anzeig., iv. (1881) pp. 518-20. 
+ Arch. de Biol., ii. (1881) pp. 342-4. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 47 


case was such a termination even unsatisfactorily observed. From a 
common trunk composed of several fibres one separated and ended at 
a muscle; here it divided into two fibrils, which each terminated in a 
‘ muscular fibre, where it formed a kind of motor plate; the arrange- 
ment, therefore, was very similar to that described by Ranvier for the 
muscles of the stomach, from which it differs only in the somewhat 
larger size of the plate. 


The Echiurida.*—Professor R. Greef is of opinion that there is 
no close genetic affinity between the Gephyrea and the Echinodermata, 
but that the former represents a distinct class allied to the Annelids 
and divisible into an armed (Hchiuride) and unarmed (Sipunculide) 

roup. 

‘ Ti this elaborate monograph he deals, after an historical and 
a bibliographical introduction, with (1) their distribution, which 
appears to be very wide, though Bonellia is confined to the Mediter- 
ranean area, and Hchiurus to the northern side of the equator. 
Their coloration can only be made out in the fresh condition as the 
pigment is soluble in alcohol. The various organs are dealt with in 
order; the presence of a central canal in the nervous system is noted, 
and it is suggested that it is a remnant of the ectodermal invagina- 
tion; fluid is to be found in this canal. A full account is given of 
the curiously minute male of Bonellia. The essay concludes with a 
systematic definition of the family, and of the three genera and fifteen 
species of which it is composed. 


Segmental Organs and Genital Gland of some Sipunculida.t— 
Dr. C. P. Sluiter discusses the question whether the so-called brown 
tubes have or have not an opening into the ceelom; after having had 
the opportunity of examining a number of fresh tropical forms, 
he has almost always been able to detect an orifice, which, however, 
was not, as is ordinarily stated, placed near the anterior, but just 
‘beside the posterior end of the tube; in only one case was the orifice 
anterior and then there was an infundibular structure developed which 
communicated by the funnel with the interior of the tube; the funnel 
proper consists of four lobes, two larger lateral, and a small dorsal 
and a small ventral; about the middle of the funnel the lobes fuse 
with one another to form the tube. In some few cases the author was 
unable to observe either an anterior or a posterior orifice; this was in 
forms in which the longitudinal musculature was not differentiated ; 
the wall of these brown tubes is, however, extremely thin, and can be 
easily ruptured. In structure the walls generally exhibit a circular 
and a longitudinal layer of muscles, and a series of radial glandular 
tubes. ‘The author describes the generative organs, and finds that the 
glands form sausage-shaped structures in a deep groove between the 
dorsal retractors; these bodies have a wall of fibres of connective 
tissue which extends and is attached to the wall of the exterior; the 
inner side of this wall is invested by a layer of small mother-cells 
from which egg-cells are regularly given off. In other forms the 
a ¥ ae Acta Acad. Czs. Leop.-Carol. Germ. Nat. Cur., xli. ii. (1880) pp. 1-172 

8.). 

f Zool. Anzeig., iv. (1881) pp. 523-7, 


48 SUMMARY OF CURRENT RESEARCHES RELATING TO 


generative glands formed ridges of connective-tissue fibres which did 
not form rounded bodies, but widely open grooves which extended 
between the muscles; on the inner face there is again a layer of 
mother-cells, which give rise to egg-cells. The male organs were 
only once observed, when they were seen to present all the essential 
characters of the female. 


Anatomy and Histology of Sipunculus nudus,*—Dr. J. Andres 
here gives a full account of his investigations, the preliminary 
notice of which we have already noted.{| With regard to its external 
form, he points out that, owing to its rich supply of muscles, the 
integument is highly contractile and that consequently the creature 
can, and does, take on the most various forms. The cuticle is 
thin, transparent, and so arranged as to be iridescent during life; 
the pores of the glands are irregularly distributed over the whole 
of the body, and vary in size according to the size of their glands. 
The pigment-spheres have been but rarely noticed, although they are 
widely distributed over the body ; varying much in dimension, they 
are seen in sections to be provided with a doubly contoured covering, 
within which there is a brown granular mass, containing a number of 
elongated oval nuclei. The circular musculature of the body does 
not consist of a continuous layer, but of a number of flattened broad 
bands, the space between which altogether disappears when the animal 
contracts in diameter. In addition to these and the longitudinal 
muscles there is a much more delicate layer of diagonal fibres, more 
widely separated from one another. The walls of the tentacles are a 
direct continuation of the proboscis, and within there is a cavity 
connected with the circumpharyngeal vessel. The value of the in- 
tegumentary cavities as the seats of respiratory activity is insisted 
upon, as is the fact that the ventral cord, unlike that of Annelids, is 
single and not double; the cord, further, presents no ganglionic 
swellings except at its termination, though, owing to its form, there 
would, on superficial examination, appear to be such. The supra- 
cesophageal ganglionic mass is biscuit-shaped, and presents distinct 
indications of having been originally double; like the ventral cord, it 
is traversed by a network of connective-tissue fibres, and the ganglia 
are most largely present on the ventral surface of the two spheres, on 
the anterior margin of the projection, and at the tip of the finger- 
shaped processes which are given off from it. 

The author is of opinion that the group of the Gephyrea is a 
natural one, that it stands closest to the Annulata, and that it is 
justifiably divisible into the two orders of the Sipunculida and 
Kchiurida. 

Sternaspis.{—In this elaborate monograph the structure and 
development of this Gephyrean is very fully treated by Dr. F. 
Vejdovsky. He distinguishes a fore- and a hind-body, and recog- 
nizes seven segments in the former and a varying number in the 


* Zeitschr. f. wiss. Zool., xxxvi. (1881) pp. 201-58 (2 pls.). 
+ See this Journal, i. (1881) p. 892. 
+ Wien. Denkschr., xliii. (1881) pp. 33-90 (10 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 49 


latter, from eight to twenty-two being there developed; but in their 
case the intersegmental grooves are not found at the sides of the 
body ; they are all provided with a single lateral row of sete. The 
hindermost part of the body is characterized by the presence of a 
ventral shield which on the ventral surface takes the place of a number 
of segments. The gill-filaments are spirally coiled and form two 
dorsal pre-anal tufts. On examining the dermo-muscular tube it is 
found that the hypodermis in the median segments forms a homo- 
geneous layer, here and there traversed by fine fibres of connective 
tissue, but altogether devoid of the unicellular glands which are so 
frequently found in this layer in Chetopods and other Gephyreans ; 
the structure of the hypodermis in other regions is also described. 
The cuticle is much thicker at the posterior than at the anterior end 
of the body and is thicker than in any other Gephyrean or Cheetopod 
known to the author. The cross-bands found on it seem to prove that 
in life the cuticle must be intensely iridescent. The surface of the 
cuticle is covered with special dermal cirri, which are continuous with 
the subjacent layer by dermal pores ; these cirri are filamentous and 
vary in form in different parts of the body; capillaries have been 
observed in some of them, and there seems to be no doubt but that 
they have a respiratory function. 

Sternaspis is distinguished from all other Gephyrea and Polychaeta 
by the peculiar disposition of its sete, which fall into three different 
groups, the arrangement, muscular supply, and development of which 
are fully described. 

The cerebral ganglia occupy the whole of the cephalic lobes; the 
ganglion-cells occupy the upper, lateral, and basal parts, while the 
fibrous substance lies between them ; there is still a close connection 
with the ectoderm. The greater part of the brain consists of cellular 
elements, which exhibit distinct bilateral symmetry; the cells vary 
greatly in form and size. The two bands of the cesophageal ring are 
proportionately long, and consist of fine nerve-fibres, without any 
ganglion-cells. The ventral cord is regularly rounded, and at first 
lies freely in the celom ; it then runs between two bands of longi- 
tudinal muscles, without giving rise to any ganglionic swellings till 
the end of the body is reached ; the complicated arrangement of the 
cells and fibres in the cord was made out by the aid of sections. 
Comparing this system with that of allied forms the author finds it to 
be intermediate between what is found in Gephyrea and Chetopods. 
On the other hand, in the character of the enteric canal Sternaspis 
stands nearer the Gephyrea than the Cheetopods. 

The vascular system is very complicated ; in addition to the two 
primary vessels, or hearts, there are a number of lateral vessels, which 
form remarkably close plexuses in all the organs, and there is also a 
special branchial system. There appear to be a pair of lateral vessels 
for each segment of the body. The segmental organs form a pair of 
brown bodies lying on either side of the cesophagus in the fifth and 
sixth segments ; they are of a spongy texture and may be seen to contain 
a quantity of refractive concretions, which prove their renal function ; 
they have no external orifices. The sexes can only be distinguished 

Ser. 2.—Vou. II. E 


50 SUMMARY OF CURRENT RESEARCHES RELATING TO 


from one another by the reddish colour of the ovaries, and the white- 
ness of the testes. They lie in the coils of the enteric canal, and are 
in both cases provided with a pair of ducts, which open to the exterior 
between the seventh and eighth segments. No directive corpuscles 
could be observed in the mature unfertilized ova. The ducts of 
Sternaspis appear to be special structures and not modified segmental 
organs. The cleavage of the egg appears to take place rapidly, inas- 
much as after sixteen hours there are seen ciliated embryos; the 
whole of the body, with the exception of the hinder end, is covered with 
very fine cilia, and a tuft of longer ones is seen at the anterior end. 
The embryo gradually grows narrower posteriorly, and the porous 
cuticle corresponds exactly to the yolk-membrane, which seems to 
grow with the body. The anterior end becomes divided into three 
lobes, of which the median is the largest. At this period the endo- 
derm fills up the whole of the tube formed by the ectoderm, and, so, 
exactly resembles the Planula of the Hydromeduse. After forty-eight 
hours the larve are twice as large, have lost all their cilia, and have 
the form of a non-ciliated Turbellarian without mouth or anus. A 
new cuticle, which has very much the appearance of a former one, is 
developed over the whole of the body ; the ectodermal cells become 
much more distinct, and those of the endoderm begin to indicate the 
formation of the enteric tube. At the hinder end of the body the two 
layers are now separated and the intermediate space is occupied with 
spindle-shaped nucleated elements, which perhaps owe their origin to 
the endoderm. After five days the cephalic lobes appear, and the 
mesoderm is found to have given rise to muscle-cells. On the sixth 
day, when the observations ceased, the excretory canals began to appear. 

In conclusion, the author thinks that there are four natural orders 
of the class Annelides : (1) Hirudinea ; (2) Oligocheta ; (3) Polycheta ; 
and (4) Gephyrea. Ina phylogenetic table he shows that he would 
derive the first two from the Discodrilida, and- the other two from 
Sternaspis ; the Discodrilida form an offshoot from the Oligochete 
stem which descends into the Amedullata, which, with Sternaspis, have 
their common origin in the Turbellaria, which, for their part, are 
derived from the Ceelenterata. The Polygordiide (Achwta Balfour) 
seem to Dr. Vejdovsky to form a group of the Polycheeta. 

The author believes that the larvee of the Chetopods and Gephyrea 
are formed on the same type, and that in Hchiurus there is a true 
segmentation of the body. 


Hamingia glacialis.*—In his detailed account of this new 
Echiurid,t Dr. R. Horst points out that the digestive tract presents a 
number of coils, that the mouth forms an elongated cleft, and that the 
conical pharynx is separated by a constriction from the cesophagus ; 
this latter is somewhat pushed to the right side owing to the great 
development of the uterus. The vascular system possesses a ventral 
vessel which accompanies the ventral end, along its whole length; a 
dorsal vessel which does not extend over more than half of the body, 


* Niederl. Arch. f. Zool., Suppl. Bd. i. (1881) 1st art., 12 pp. (1 pl.). 
+ See this Journal, i. (1881) p. 891. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 51 


and a neuro-intestinal anastomosis, by means of which the two primary 
trunks communicate with one another. The ovarian tubes agree gene- 
rally with those of the other Echiuri, and the tubes, being in the 
specimen examined filled with ova, had a yellowish colour. Just as 
in Kchiurus, the proper covering for the egg which is found in Bonellia, 
is completely absent. The author is unable to make any statement as 
to the male organs. 


Echinorhynchus.* — P. Méegnin states that the menisci of this 
parasite open at the base of the proboscis by a large buccal pore; in 
H. brevicollis the menisci are replaced by two long cylindrical tubes 
which open into a groove at the base of the proboscis, and extend as 
far as the hinder extremity of the body; they are clothed internally 
by polygonal cells, and the whole arrangement strongly calls to mind 
the bifurcated intestine of some Distoma. This intestine, which is to 
- be seen in encysted larvee and, undergoing atrophy, is only representcd 
by the menisci in the adults of most species, persists in certain forms. 
The author thinks that this arrangement indicates some affinity of the 
Acanthocephali with the Trematoda, and separates them from the 
Nematodes, with which order they are frequently placed. 


Proscolex of Bilharzia hematobia.j—J. Chatin states that the 
ovum is regularly oval, and has a kind of apical tubercle at one 
pole, a character which is extremely rare among the Trematoda 
digenea, though common enough among the T. monogenea. ‘I'he 
infusoriform character of the larva is pointed out, and the anterior 
end is stated to become shortly differentiated into a caecum which 
projects into the body-cavity, and which the author, agreeing with 
Dr. T. 8. Cobbold, looks upon as being the first rudiment of the diges- 
tive tract. This being, then, possessed by the larval form, it should 
rather be spoken of as scolex (Rédia) than as proscolex; and this 
view would be strengthened by the certainty of the sarcode spherules 
being, as the author thinks they are, young gemme in course of 
development. These amcebiform bodies are shown not to have the 
special outer layer of the simpler organisms (Amcebe), but rather a 
cuticle distinctly differentiated, and not unlike the protecting layer 
which we find on the young Cercarie developing within a sporocyst 
or a Rédia. 


Nervous System of Cestoda.{—In the third part of his account 
of his investigations into this system of the Platyhelminthes, Dr. A. 
Lang deals especially with the Tetrarhynchi, which he chose on 
account of the notorious difficulties which are associated with the 
investigation of the Tzeniadz, and because of the promise of a well- 
developed nervous system given by the large amount of muscular 
tissue in the scolex, and of the large size of some of the species. 
Difficulties, however, were not evaded; nothing of value can be 
obtained by maceration, and nothing at all by examination of living 
specimens. Transverse sections carefully made gave good results. 

* Comptes Rendus, xciii. (1881) pp. 1034-6. 


¢ Ann. Sci. Nat. (Zool.), xi. (1881) art. No. 5, 11 pp. (1 pl.). 
{ MT. Zool. Stat. Neapel, ii. (1881) pp. 372-400 (2 pls.). 


E 2 


52 SUMMARY OF CURRENT RESEARCHES RELATING TO 


The following forms were examined :—(1) Rhynchobothrium corol- 
latum, from the intestine of Mustelus levis ; (2) Scolices of Tetrarhyn- 
chus, from the muscles of Orthagoriscus mola (probably T. gracilis) ; 
(8) Anthocephalus elongatus, from the liver of the same fish; and (4) 
Anthocephalus reptans, from Symnus lichia. 

The scolex may be divided into three parts: (a) a cephalic region, 
which carries the sucker ; (b) a cervical region, containing the sheaths 
of the proboscis ; and (c) a bulbous region, which carries the swellings 
of the proboscis. In the first of these we find in the more anterior 
sections four outer cephalic and four inner cephalic nerves; in the 
succeeding sections these eight nerves are thicker and more distinct, 
two are now approaching the region of the cerebrum; in the next 
section we find on either side a commissure between the upper and 
lower internal cephalic nerves; then one between the upper and lower 
outer nerves ; within these commissures there are small bipolar gang- 
lionie cells with a large nucleus and a distinct nucleolus. The inner 
cephalic nerves give off smaller ramules. 

Further back, not only are the four upper connected by commis- 
sures with the four lower nerves, but the two inner, on either side, 
are connected by a transverse band with the two outer. From the 
outer angles of the squarish mass thus formed a strong nerve is given 
cff which passes to the sucker. As yet, the two halves of the cerebrum 
appear to be independent; but, further back, there are two connecting 
commissures. Still further back sections are found to exhibit a 
united transverse commissure, which gives rise to a band-shaped 
cerebral mass, enlarged towards its middle and at either end. 

The author then compares this account of what obtains in T. gracilis 
with the arrangements which are found in the other forms that he 
examined. 

Passing to the cervical portion of the scolex, we find the two 
longitudinal trunks which arise from the brain; they lie, on either 
side, within the dermo-muscular tube, between the ascending and 
descending water-vessel. Here and there they give off delicate nerves 
which, generally, pass off to the dermo-muscular tube. The author 
directs attention to the presence of a somewhat disturbing element on 
the inner side of the nerves; these appear in section as dotted masses ; 
they turn out to be the united efferent ducts of the large number of 
gland-cells which are imbedded in the parenchyma of this region of 
the body. ; 


In the bulbous portion the longitudinal nerves present much the ~ 


same arrangement as in the cervical part, and the chief interest centres 
in the branches which are given off from them; the separate fibres of 
these enlarge here and there into very long and large ganglion-cells. 
In the proglottides the lateral nerves extend to the end of the chain, 
retaining their former relative position; they are best developed in 
the more anterior joints, in which the generative organs are still 
feebly developed. ‘Towards the hinder end they become more in- 
distinct. 

After some critical remarks on the observations of earlier observers, 
the author passes to Amphilina, an unjointed Cestode; the spongy 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 53 


cords which Salensky, following Sommer and Landois, regarded as 
water-vessels, are regarded as true nerves; in longitudinal sections 
their course can be easily followed; the longitudinal nerves extend 
through the whole of the body and unite at the posterior end. They 
give off outwards at short distances small ramules, which probably 
innervate the dermal musculature, and they also occasionally give off 
internal branches. Some little way behind the anterior end of the 
body the nerves give rise to a small thickening, which becomes united 
by a commissure with its fellow of the opposite side. From the 
thickened ends of this cerebral commissure a well-developed nerve 
passes forwards, to supply the most anterior end of the body and the 
muscular walls of the sucker. There is, on the whole, a not incon- 
siderable resemblance to what obtains in the Trematoda. 

In conclusion, Dr. Lang sums up the state of our knowledge as to 
the nervous system of the other Cestoda: T. perfoliata has a better 
developed nervous system than the rest of the Teeniade; the anasto- 
mosis or cerebrum contains nuclei and fibrils, gives off two lateral 
primary trunks, and completely resembles in structure the same parts 
in the Nemertinea; T. solivm, with others, has three cords on either 
side. In the Bothriocephalida the water-vessels are on the outer 
side of the longitudinal nerves, and here also the anastomosis is 
concave anteriorly ; in the Ligulida the connecting commissure forms 
a pretty broad bridge, the lateral trunks le outside the water-vessels, 
and are approximated towards one another in the anterior region of 
the body. 


Development of the Ovum of Melicerta.*—-L. Joliet points out 
that the development of the embryo of Rotatoria has as yet been 
studied in only two genera—Brachionus by Salensky, and Pedalion by 
Barrois. The mode of segmentation is still unknown. 

Although the author has ascertained f that the development of the 
winter-ege and of the male egg agrees in a general manner with that 
of the female summer-egg, it is more especially on this last that his 
researches have been made. 

Within the maturation-sac it presents, in the middle of the 
germinal vesicle, a small but very distinct germinal spot. After 
deposition this spot speedily disappears. It did not appear to the 
author that there was any emission of a polar globule. The first 
segmentation-plane perpendicular to the major axis of the egg, which 
is an irregular ovoid, divides it inté two very unequal segments, 
Afterwards the two segments divide symmetrically, and so that each 
furnishes eight of the spheres which constitute the egg in the stage 
xvi. The spheres derived from the larger primary segment are larger 
than the others, and also larger in proportion as they are further from 
the animal pole. Hach would appear to have, so to speak, a certain 
degree of animality. Throughout the whole duration of the segmen- 
tation, the part played by the nuclei and the asters is very remark- 
able. A rotatory movement, already noted by Barrois in Pedalion, is 


* Comptes Rendus, xciii. (1881) pp. 856-8. 
+ See this Journal, i. (1881) p. 894. 


54 SUMMARY OF CURRENT RESEARCHES RELATING TO 


also observable, which tends to transport the spheres derived from the 
small segment from the animal pole to the opposite one, skirting the 
dorsal face, while the large spheres give place to them and glide along 
the ventral face. 

At the stage xvi. the egg is composed of a row of four small cells 
derived from the small segment and occupying the dorsal face, of four 
spheres, larger and larger, occupying the ventral face, and of two 
rows of four cells placed on the sides, and four derived from the large 
and four from the small segment. 

It is only after this stage xvi. is reached that the dorsal and 
lateral cells commence to multiply much more rapidly than the 
ventral ones, and to spread over their sides. In proportion as these 
small cells glide over the surface of the large ones, the latter sink 
with an oscillatory movement, which at first removes the smaller 
ones, until at length the last and largest glides in its turn under the 
first, leaving an orifice, the blastopore, which remains visible for some 
time almost exactly at the spot where, later on, the mouth is formed. 

By the very place which it occupies from the moment of the 
closing of the blastopore, it is easy to see that the last sphere 
enveloped corresponds to the intestine, which it will serve to form, if 
not entirely, at least in great part. 

In the same way, by the manner of their inclusion, the two large 
spheres following will be on the ventral face of the first, in the situa- 
tion which the genital organs will occupy. Later on, when the 
spheres begin to divide and subdivide, this disposition becomes very 
obscure; but for a certain time after the closing of the blastopore it 
remains perceptible, and shows that the embryo is formed, if not of 
continuous layers, at least of masses of tissue which obviously corre- 
spond to the endoderm, mesoderm, and ectoderm of the higher animals 
both in their position and destination. 

When the subdivision has been pushed to its furthest limit the 
egg presents the form of a finely moruloid mass, in which can only 
be recognized an outer light layer and a darker central one. The 
cephalic region always remains lighter. The blastopore is no longer 
distinguishable. 

Soon, along the side and ventral face an oblique furrow appears 
which constricts the mass and separates the tail; the latter is thus 
folded under the ventral surface and directed towards the head, as in 
the embryo of Brachionus and Pedalion. 

About the level of the caudal extremity a depression appears in 
the cephalic mass; it is uncertain if it corresponds to that described 
by Salensky in Brachionus, but it indicates the appearance not of the 
mouth but of the vibratile pit situated under the lip in the adult. 
A little later, and somewhat higher up, the mouth appears, as a 
depression sufficiently sunk, without doubt to form the mouth, but 
certainly not sufficiently to form the mentum. Yet later, and also on 
the back, the cloaca is formed by an invagination of the ectoderm, 
and this, though very long in the adult, is as yet very short in the 
larva, and remains reduced to a simple emargination in the Floscu- 
lariew. The cephalic region is soon defined by a slight fold, which 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 55 


indicates the margin of the chitinous covering. The eyes appear as 
two red points; cilia commence to move, at first on the infra-buccal 
pit, then on the mouth, and finally on the top of the head, where they 
form a circlet. The armature of the mastax comes into existence, the 
tail retires little by little towards the extremity of the egg, whose 
envelope it finally ruptures. The larva has been already described by 
several authors, and M. Joliet only insists on the fact that, like the 
larva of Lacinularia figured by Huxley, it presents cilia on three parts 
of its body; a continuous, and at this time scarcely sinuous circlet 
placed above the mouth; a second circlet surrounding this and the 
mouth, stretching even over the vibratile pit; lastly, a tuft of cilia at 
the extremity of the tail. The larva remains active for some hours, 
and then becomes fixed by means of the glands enclosed in its tail. It 
then commences to collect in its vibratile pit the minute particles held 
in suspension in the water, mixes them with the secretion from the 
gland, hitherto taken for a ganglion, and, according to the judicious 
observations of Gosse and Williamson, therewith forms the pellets 
which, when juxtaposed, constitute the tube it inhabits. 


Echinodermata. 


Development of the Skeleton of the Ophiurida.* — The first 
point to which Prof. H. Ludwig addresses himself is the development 
of the arm-ossicles ; these he has previously stated to be originally 
double, but he has never till now been able to demonstrate this by a 
reference to embryological data, though the discovery by Lyman of 
deep-sea forms in which these ossicles were distinctly double has 
afforded considerable support to Dr. Ludwig’s doctrine. The form 
best adapted for investigation is the viviparous Amphiura squamata. 

As is well known, the arms of the Ophiurid grow at the tip; the 
first rudiment of the ossicle consists of two calcareous pieces symme- 
trically placed on either side of the middle line of the arm, and each 
has somewhat of a triangular form; one ray is directed aborally in 
the long axis of the arm, the other two look adorally, and form 
between them a smaller angle than each of them forms with the aboral 
piece; these two do not, however, lie in the same plane, but one is 
dorsal and the other ventral, the former being further median and the 
other lateral in position. At an early period a distinct difference may 
be seen in the size of these three rays; the aboral becomes longer 
than the adoral rays ; the form of the whole piece changes, owing to the 
development of calcareous processes, which sooner or later fork at their 
free end, and become connected with the ends of neighbouring forks, 
so as to give rise to the reticular tissue characteristic of the Echino- 
dermata. In this way the two adoral pieces become connected together. 
Soon, too, the aboral process begins to form meshworks. This mode 
of growth not only takes place laterally but also mesially, so that 
the ends of the adjoining ossicles come into direct contact, without, 
however, fusing. Later on, this fusion commences both at the aboral 
and adoral ends: in their middle there is a space with concave sides, 
which only becomes completely filled up at a later stage. 


* Zeitsch. f. wiss. Zool., xxxvi. (1881) pp. 181-209 (2 pls.). 


56 SUMMARY OF CURRENT RESEARCHES RELATING TO 


The relations of the ossicles to the radial water-vessel and_ its 
lateral branches are, further, of special importance; this vessel lies, 
from the first, ventrally to the rudimentary ossicles, and it is only 
after some time that the branches to the feet become surrounded by 
calcareous tissue; in other words, the branches of the radial vessels 
have at first the relation which they retain throughout life in the 
Asteroidea. 

After some further consideration of these points, the author passes 
to the terminal plate of the arm, as to which he has convinced himself 
of the accuracy of J. Miller’s doctrine that this piece has primarily a 
groove on its lower surface, and that it is only later on that it becomes 
converted into a ring. The later observations of Prof. Ludwig have 
convinced him of the accuracy of his comparison of the lateral plates 
of the arm of an Ophiurid with the adambulacral pieces of an arm of a 
star-fish. 

The ventral plates are reported to commence as a small tri-radiate 
body lying exactly in the middle line of the arm, with one aboral and 
two adoral rays; these, then, notwithstanding opposing statements, 
are unpaired pieces. The same is true of the dorsal plates. 

The interesting oral pieces of the skeleton are truly the modified 
first ambulacral pieces; a young Amphiura exhibits the possession of 
nine skeletal pieces for each ray; one of these is terminal and un- 
paired, the other eight lie in four pairs symmetrically on either side 
of a middle line; of these two, more feebly developed, lie closer to 
the median plane of the radius, and more deeply in the body; the 
other two are better developed, and le more superficially ; the former 
are the first two ambulacral, the other the first two adambulacral 
pieces. The second pair of ambulacral pieces becomes more strongly 
developed than the first pair, the two pieces of which, later on, form 
thin calcareous plates, which descend further and further into the 
angles of the mouth, remain separated from one another, and, still 
later, give rise to the two peristomial plates. The second pair unite 
together and become connected with the first adambulacral pieces to 
form the tori angulares. 

The first skeletal pieces to appear on the dorsal side are the five 
terminal plates of the arms; internally to them come the five primary 
radials; the central piece usually appears later on; the intermediate 
skeletal plates appear around the central. The so-called radial shields 
of the adult appear early at the outer edge of the radials. The author 
points out the similarities in position between the primary madreporie 
pore of Amphiura and the corresponding structure in the larva of 
Antedon. 


Asterias.*—In the first part of his ‘ Contributions to the Systematic 
Arrangement of the Asteroidea,’ Prof. F. Jeffrey Bell discusses the 
species of the genus Aséerias; after giving a list of the 77 known 
species, and of the 34 well-recognized synonyms, the author proceeds 
to suggest an arrangement for breaking the species up into groups ; 
He first separates the species “into those in which there are developed 


* Proc. Zool. Soc. Lond., 1881, pp. 492-515 (2 pls.). 


ee 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 57 


more than five rays, and those in which, so far as we know, the 
number five is constantly retained.” For these two groups the terms 
Heteractinida and Pentactinida are suggested. Among the former 
we find that some of the species have more than one madreporic 
plate; the secondary divisions, therefore, are named polyplacid and 
monoplacid. The value and character of the number of rows of 
adambulacral spines is next discussed, and the terms Monacanthida, 
Diplacanthida and Polyacanthida are applied to the forms in which 
there is one, two, or more than two such rows. Some species are 
shown to have their madreporic plate encircled by spines, and these 
forms are distinguished as being echinoplacid. The next character 
used depends on the arrangement of the spines, “on special local 
modifications of the integument, which may be known as special 
plates”; such forms are autacanthid; those in which the more 
ordinary arrangement obtains are known as typacanthid. The last 
character used for the formation of small groups depends on the 
form of the spines on the abactinal surface; and here we have 
simplices, rarispinose, obtusispinose, and acutispinose. 

After a table, in which this system of grouping is worked out, 
the author passes to the “ mode of formulating results,” using a certain 
number of symbols, and distinguishing heteractinid from pentactinid 
forms by placing over their formule the mathematical sign of the 
square root. Short formule: are given for most of the known 
species. Thus, for the well-known A. rubens, we have the formula 
2 ats, for it is diplacanthid (2), anechinoplacid (a), typacanthid (8), 
with simple dorsal spines (s). Again, /1 > is sufficient to distinguish 
A. calamaria as a monacanthid, polyplacid, heteractinid form. “If 
we know, as we do in this case, further details, we may write the 
formula 1 paa’; or, in other words, in addition A. calamaria 
has no spines round its madreporic plate, and the dorsal spines are 
placed on special plates.” 

The author then makes some observations on the species of 
Asterias, found in the British seas, and concludes with the description 
of five new species: A. philippii, A. inermis, A. verrilli, A. spirabilis, 
and A. rollestoni, for all of which, as also for A. japonica, of which a 
description is given, the author gives the “ general formula.” 


Spines of Asteroidea.*—At the conclusion of a description of a 
new species of Archaster (A. magnificus), Professor F. J. Bell points 
out that in littoral species, at any rate, the strength and number of 
the spines is in inverse proportion to the stoutness of the skeletal 
plates; when these are strong the star-fish is enabled to withstand 
the bite of an enemy ; but when they are weaker, a defensive apparatus 
is provided in longer, stronger, and stouter spines. 


Ccelenterata. 
Prodrome of the Anthozoan Fauna of Naples.t—-Dr. A. Andres 
here gives a systematic catalogue of the species, with synonymy, «c., 


* Ann. and Mag. Nat. Hist., viii. (1881) pp. 440-1. 
+ MT. Zool. Stat. Neapel, ii, (1881) pp. 305-71. 


58 SUMMARY OF CURRENT RESEARCHES RELATING TO 


an alphabetical index of species and synonyms, a bibliographical list, 
and an index of authors. 


Metamorphoses of Cassiopeia borbonica.*— Professor G. Du Plessis 
has observed ova of what he believes to be this species, develope into 
a fixed Scyphistoma, after passing through a free Planula-stage. 
Other larve of similar appearance, which had already attained the 
Scyphistoma-stage, were studied by him at the Naples Aquarium, and 
were seen in the middle of October to divide metamerically into 
segments, forming the well-known Strobila-stage. The segments 
soon became detached, constituting free Ephyre of a similar, but 
paler, yellow tint to that of the adult of the above species, but differ- 
ing from it in having four simple and suckerless, instead of eight 
ramified arms, and in having the margin of the umbrella much more 
deeply notched. In this instance also, the attempt to rear the adult 
failed, but as the only other species whose stages resemble these, has 
quite a different Ephyra, there seems good ground for believing that 
we have here the full metamorphosis of a Medusa, supposed hitherto 
to develope ametabolically. In the agreement of its physiological 
arrangements with those groups with which it has hitherto been 
classed, it affords an argument in favour of the morphological correct- 
ness of the present classification. 


Development of Geryonopsida and Eucopida.}t—-Professor C. Claus 
states that in an aquarium containing sexually mature specimens of 
Octorchis gegenbauri, Irene pellucida, and Aiquorea forskalea, he saw 
small polyp-stocks which presented great resemblance to Campa- 
nulina; the elongated hydranths were placed on branched stolons, 
the periphery of which was invested by a more or less distinct 
periderm. ‘There was a conical retractile proboscis, and the base of 
the contractile tentacles was surrounded by a delicate ectodermal 
fringe. Hydrathecz were, however, altogether wanting; this and 
other differences induce the author to call this form Campanopsis. 
The medusa-buds arise on the middle of the body of the polyp, where 
they form one, two, or, rarely, three transverse rows; they appear as 
bilaminate rounded projections, the base of which soon grows into a 
long cylindrical stalk, with a vesicular endoderm. Before the forma- 
tion of the subumbrellar cavity, the ectoderm gives rise to a layer of 
flat cells, which form the theca, and give rise to a closed mantle- 
covering. The manubrium is formed from a central elevation; the 
radial vessels give rise to outgrowths, which are the rudiments of 
the primary marginal tentacles. In alternate rays, as well as between 
these and the primary tentacles, marginal vesicles become developed 
with small intermediate thickenings—the rudiments of fresh marginal 
filaments. When, therefore, the medusa is set free, it has two long 
tentacles and eight adradial marginal auditory vesicles. These last, 
which are relatively large, contain each a single otolith. At this 
point, unfortunately, the author’s direct observations cease, but he 
adduces reasons for believing that this Campanopsis is an Octorchis. 


* Bull. Soc. Vaudoise Sci. Nat., xvii. (1881) pp. 633-8 (1 pl.). 
+ Arbeit. Zool. Inst. Wien, iv. (1881) pp. 89-120 (4 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 59 


In some notes on the development of Irene pellucida, which is so 
common in the Adriatic from October to March, Claus states that 
it is possible that the polyp-form of this Medusa is a Campanulina. 
The first rudiment of the tentacles appears as an outgrowth, present- 
ing brownish granular concretions, and having a pore at its tip; 
these pores are looked upon as being the orifices for subjacent glands, 
which probably have the function of renal organs, and which are 
formed by the endodermal investment of the adjacent portion of the 
circular vessel; by direct observation one may convince oneself that 
the brown granules and refractive concretions do escape by these 
pores to the exterior. The genital products appear to become matured 
im specimens of very various sizes. Some notes on Phialidium 
variabile complete the paper. 


Fission of Phialidium variabile.*—Dr. M. Davidoff states that 
he has observed in this Leptomedusa that a second stomogastrium 
becomes formed at the base of the stomach as a small downwardly 
projecting bud; this happens before the tentacles are all developed. 
The bud gradually grows, and after some time a mouth breaks 
through. The whole medusa now commences to elongate, and the 
stomogastria occupy the centres of the ellipse; two radial canals 
now open into each stomach and between the two mouths there is 
an intergastral canal. After these and other changes are effected, 
the creature is ripe for fission ; the plane of division lies between the 
two stomogastria, and almost always at right angles to the long axis 
of the ellipse; the constrictions deepening, the medusa is divided 
into two nearly equal halves. In some cases there is a third stomo- 
gastrium developed. The author reminds us that Kélliker, many 
years ago, noticed a process of fission in Stomobrachium mirabile. 


Crambessa tagi.t—Professor R. Greef points out that this 
Portuguese Medusa affects the mouths of rivers, and makes its way 
into landlocked bays. He has found a wide vessel running within the 
oral fold; the two pairs of vascular branches which are given off 
from the short central transverse vessel, open, together with the eight 
arm-yessels, in the central cavity ; the outgrowths above these central 
oral vessels have just the same structure as the lobes of the arms, 
into which they pass directly, and may therefore be regarded as 
“sucking knobs” or oral frills. Hach of the eight arm-vessels 
divides into four longitudinal vessels, one of which is median; the 
three peripheral ones are connected by transverse anastomoses with 
the axial, and give off branches to the appended lobes. 

The eight sensory organs agree in their external and general 
internal structure with those of the Hertwigs’ second group of 
Acraspedota; the terminal network, in which the crystals lie, is 
regarded by the Hertwigs as being formed from the vessel which 
runs along the arm; Greef, however, thinks that this plexus is 
formed from the mesoderm, while the nerve-band breaks up into a 
fine nucleated plexus, which makes its way into the meshwork which 


* Zool. Anzeig., iv. (1881) pp. 620-2. 
t Ibid., pp. 568-70. 


60 SUMMARY OF CURRENT RESEARCHES RELATING TO 


supports the crystals, and so comes into contact with them. In the 
upper wall of the terminal knob the author was able to detect an 
ocellus. 


Sexual Cells of Hydroida.*—A. Weissmann finds that these are 
ectodermal in origin, but he allows that in some cases they are 
developed in the endoderm, and that in others the spermatozoa are 
ectodermal and the ova endodermal in origin ; and he also recognizes 
the cceenosarcal origin of the elements in some cases. Together with 
this ccenosarcal origin, there may be development from cells situated 
in the sexual buds (blastoid origin), and Hydrozoa may therefore be 
spoken of as cenogenous (abbreviated from ccenosarcogenous), or as 
blastogenous ; and the author insists on the correctness of the view 
that in some cases the germ-cells are not developed until the medusa 
is completely formed. 

The chief object of the present communication is to demonstrate 
that the sexual cells which arise in the ccenosare are normal produc- 
tions of great significance, and that in all such cases the coenosare and 
not the gonophores is to be looked upon as the true seat of the cells ; 
and, further, to show that this mode of reproduction is very common, 
there being entire families in which the ova are so formed; while 
there are others in which the testicular products also are so developed. 
Of the latter, Plumularia (e.g. P. echinulata) is an example, for in it 
the cells are developed in the endoderm, principally of the trunk 
portion, but often also at the base of the lateral branches of the 
coenosare. The formation of the male and female gonangia is 
described in detail, and shown to be similar for both. 

Gonothyrcea loveni is the first example of the Campanularide, and 
here the male elements are ectodermal, and arise, not in the ccenosare, 
but in the gonophores, from an invaginated set of ectodermal cells. 
The ova, on the other hand, are formed from the endoderm of the 
ccenosare and of the branches. In Hudendrium ramosum they are 
both formed from the endoderm, but the male elements are of 
blastoidal and the female of ccenosarcal origin. In Cordylophora 
lacustris, as Schulze was the first to show, the ova are ccenosarcal and 
ectodermal ; the origin of the male elements has not been accurately 
worked out. 

We find, then, certainly that in most (cf. next note) polyps with 
fixed gonophores the ovules do not arise in the gonophores but in the 
coenosare, and their appearance is the condition of the formation of a 
gonophore, into which they migrate. There is more variation in the 
male products, which do not appear to be so constantly ccenogenous; 
where, however, they are so, the development of the gonophore and 
the migration of the testes into them is essentially similar to that of 
the ovaries. 


Spermatozoa of Hydrozoa.t— A. de Varenne has examined 
Campanularia flexuosa, Gonothyrea loveni, and Podocoryne carnea, in 
which are found respectively a fixed gonophore, a demi-medusa, and 


* Ann, Sei. Nat. (Zool.), xi. (1881) art. 6, 33 pp. (3 pls.). 
t+ Comptes Rendus, xciii. (1881) pp. 1032-4. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 61 


a free medusa. In all cases the mother-cells do not appear in 
any part of the gonophore, but in the ccenosare. Taking the first- 
named species, he found that before the appearance of any gono- 
phore large highly-refractive cells appear in the endoderm of the 
ceenosare ; the presence of a certain number of these mother-cells 
determines the formation of a gonophore. Very soon the primary 
mother-cells multiply with great rapidity, and the daughter-cells, 
which are much smaller, form a horseshoe-shaped testicular mass, 
which, growing rapidly, ceases to form part of the endodermic wall, 
owing to the reconstitution of the unaltered endodermal cells, which 
now form a continuous layer below it. This explains the origin of 
the statement that the testicular cells are ectodermic in origin. 
There is, further, a great similarity between the development of the 
male and female elements. The author thinks that there is no true 
alternation of generations. 


Porifera. 


Attempt to Apply Shorthand to Sponges.*—The system here 
elaborated by Dr. G. C. J. Vosmaer is an extension of that first intro- 
duced by him in a paper on the Desmacidine of the Leyden Museum,t+ 
and its object is to give shortly the characters of a sponge by symbols 
which denote its several spicules. In the present scheme he tries to 
make his system of symbols so elastic as to admit almost any possible 
combination of characters in a spicule. Of course it is only applicable 
to sponges which have spicules, and does not take account of the 
Carnosa or the Horny Sponges; neither does if take account of the 
proportions (though the worker may readily add these himself); the 
author admits that it is not applicable to all cases, but claims for 
it the recommendation of saving some time and trouble in description. 
It is impossible to give here all the full formule used, so that in most 
cases only the abbreviations are given, which can be combined 
according to the requirements of different cases, and may help 
students of sponges to arrange for their own use, at any rate, methods 
of expressing shortly the often complicated spicular complements 
which may be met with. Dr. Vosmaer has used it for three years. 

For monaxial (i.e. linear) spicules are used :—tr (truncate) = 
blunt-ended ; ¢r tr = blunt at both ends, but not to same extent; tr ac 
(acute) = blunt at one end, pointed at the other (acuate, Bowerbank) ; 
acac = doubly-pointed, to different extents. Where the forms of the 
ends are similar, the formula is fr, ac*, &c.; tr® tr = clavate or 
spinulate cylindrical, and tr° ac stands for the common spinulate or 
“ pin-like ” form; f = fusiform, sp = spined. Combinations of these 
signs supply formule for the thirty-two modifications of straight mon- 
axial spicules. For curved forms of the same group the following 
abbreviations are used. An inverted V (/\) for the tricurvate acerate, 
an § on its side (®) for the bihamate; the same with two lines 
drawn across it, so as to make it resemble the sign for a dollar, stands 
for trenchant contort bihamate ; anc is anchorate, anc* is tridentate 


* Tijdsch. Niederl. Dierk. Vereen., v. (1881) pp. 197-206 (1 pl.). 
+ See this Journal, iii. (1880) p. 661. 


62 SUMMARY OF CURRENT RESEARCHES RELATING TO 


anchorate, anc?3 being tridentate equi-, and anc anc 3 tridentate 
inequianchorate; anc 2 is bidentate anchorate. Rut (rutrum, a 
shovel) palmated anchorate. 

For the Hewactinellid, or, as Vosmaer prefers to call them, 
Triactinellid, types (those with three distinct axes), the general de- 
nomination is ha (initials of é£ and afwv) ; the different radii are desig- 
nated by R or r; thus when four of the six rays are small and two 
large, the formula for the spicule is (4r-++ 2B); sp may be added 
for spined. Where the spicules are fixed, i.e. skeletal, a line is 
drawn over the formula; thus the skeleton spicule of Farrea becomes 
ha (4R-+ 2rsp); but the “fir-trees” of Hyalonema, &c., become 
ha (4r + Rf sp). 

For Tetractinellid forms the general sign ta is used (réocapes, 
aéwv); in the common case in which one ray is longer or shorter 
than the rest, this odd ray is termed M (manubrium), and the others 
d (dentes); if these are bifurcate, bif is added to d. For the angles, 
that which M makes with the three d’s—almost the only angle which 
varies—is termed 6; > is greater than, < is less than. A triradiate, 
being reckoned as a tetractinellid with one ray aborted, is expressed 
by ta (M = 0). Thus porrecto-ternate of Bowerbank is ta (6 > 90°), 
patento-ternate is ta (p = 90°), recurvo-ternate (¢@ < 90°); bifurcated- 
ternate is ta. d. bif. If necessary, such a formula as ta (¢ > 90°) 
d. bif (d' > d < M) could be used, where the three rays are bifureate 
and of different sizes, but less than the odd ray. 

Polyaxial forms, i.e. globates and stellates, may be termed gl 
(globulus) or s¢ (stella), globo-stellates (with large ball for a centre) 
gl. st. For the spiral or double stellate (e.g. of some Suberitide), st? 
is employed. 

Protozoa. 

Flagellata.*—J. Kiinstler states that in an incubating chamber 
Cryptomonas ovata germs found at different stages in development 
presented the following characters. The less advanced were formed 
by a nucleolus surrounded by a layer of protoplasm; soon one of their 
poles developed more rapidly than the other, and elongated. After 
it had reached a certain size it gave rise at its free extremity to an 
axial cord of protoplasm, which constitutes the first stage of the diges- 
tive tube. Here there appear some large vacuoles, which divide and 
rapidly multiply, and soon a cavity commences to be developed in the 
body, beginning as a lateral space, one on either side. In Chilomonas 
paramecium there is, similarly, a vestibule to the digestive tube, an 
antero-lateral constriction, locomotor, striated, and other prehensile 
flagella, a stomach with granular walls, an intestine terminating in 
an anus, four tegumentary layers, and a nucleus with several nucleoli, 
whence is given off a tube which dilates into the incubating chamber 
in which the germs are developed. In Chlamydomonas pulvisculus 
there are four, and not two, striated flagella, which are inserted 
around an orifice leading into a small cavity, and giving off delicate 
tubes to the contractile vesicles. 

A new species is Astasia costata, the ribbed form of which is due 


* Comptes Rendus, xciii. (1881) pp. 746-8. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 63 


to the presence in their integument of regular rows of starch-grains. 
In this form the digestive apparatus consists of a narrow cesophagus, a 
large gastric pouch, the walls of which were not detected, and an 
intestine leading to an anus. A new generic form is represented by 
Kiinckelia gyrans, which is a fresh-water Noctiluca. The body is 
capable of elongation, and so is enabled to creep about. There is an 
enormous tentacle which exhibits very active movement when the 
animal isswimming. Under its cuticle there are two muscular layers, 
which are continued into the tentacle. The mouth appears to lead 
into a very large cavity. No phosphorescence has yet been observed 
in this form. 

Infusoria Parasitic in Cephalopods.*—In an elaborate memoir, 
A. Foettinger enters more into detail into some of the characters of 
these forms.t In dealing with the suspected muscular fibrils, he says 
that in optical section they reveal themselves as bright spots, set at 
equal distances from one another, and placed near the cuticular 
envelope. ‘They give rise to the appearance of a transverse striation; 
and these striz, of which there are two systems, become both visible 
when the cover-glass is compressed on the animal. ‘T'he differences 
in the position of the fibrils is due to a difference in their state of con- 
traction ; for as they contract their obliquity diminishes, and the part 
of the body which contains them becomes shorter and wider. In one 
case the author observed in Benedenia a nucleus extending through- 
out the whole length of the body. He regards the nucleus, the 
characters of which have been already detailed, as not forming a fixed 
element, but one gifted with the power of amcboid movements. 
Opalinopsis sepiole was on one occasion observed to conjugate and 
reproduce while in sea water, so that in this case we can see how the 
parasite may pass from one Cephalopod to another. 

Parasites of the Echiurida.t—Professor R. Greef describes Cono- 
rhynchus gibbosus nov. gen. et sp.,a large Gregarine to which he pre- 
viously gave the name of Gregarina echiuri. The creature, which 
lives in the digestive canal, is nearly always found, when adult, in 
conjugation. Hach individual forms a hemispherical disk, and its 
surface is provided with a number of conical and warty projections. 
At the anterior end there is a considerable process which appears 
to serve as an organ of attachment; the form is completely trans- 
parent owing to the great development of vacuoles. There is a large 
nucleus. In size each adult is about 1 mm. long and 1 mm. broad. 
In the youngest stage observed, the Gregarine had the form of a Mono- 
cystis agilis, and the internal substance was opaque and darkly 
granular. Distomum echiuri n. sp., found in the seminal vesicles of 
Echiurus pallasi, is 2 mm. long, and is continued forwards anteriorly 
into a proboscidiform process. Nemertoscolex parasiticus n. gen. et 
sp., is a Nemertine of about 3 mm. long, found twice in the ceelom of 
E. pallasi, in the male as well as in the female. 

* Arch. de Biol., ii. 1881) pp. 345-78 (4 pls.) 

+ See this Journal, i. (1881) p. 902. 


¢ Nova Acta Acad. Cas. Leop.-Carol. Germ. Nat. Cur., xli. ii. (1880) ‘pp. 
128-131, with figs. 


64 SUMMARY OF CURRENT RESEARCHES RELATING TO 
BOTANY. 
A. GENERAL, including Embryology and Histology of the 
Phanerogamia. 


Origin of the Embryo-sac and Functions of the Antipodal 
Cells.*—-After referring to the views on these subjects already pub- 
lished by Warming, Vesque, Strasburger, Fischer, Ward, and Treub,t 
L. Guignard details a series of observations of his own on a variety of 
plants, to determine some of the controverted points. 

As a type of the Mimosez, in which the phenomena are remark- 
ably uniform, he takes Acacia retinoides. At the summit of the 
nucellus, beneath the epidermis, an axial cell, somewhat larger than 
the adjoining ones, divides into two superposed cells; one, the origin 
of the cap (calotte) in Dialypetale, in immediate contact with the 
epidermis ; the other Warming’s primordial mother-cell of the embryo- 
sac, situated at a greater depth; these he calls the apical and sub- 
apical cells. The apical cell gives birth to a tissue which is generally 
reduced to three broad cellular layers. The subapical cell rapidly 
enlarges, and becomes segmented horizontally in the basipetal direc- 
tion, dividing thus into three superposed cells each equal in size to 
the mother-cell. Of these the lowest is alone the true mother-cell of 
the embryo-sac, enlarging at the expense of the others and of the 
lateral nucellar tissue. The nucleus increases in size, and beeomes 
surrounded at first by granular protoplasm, then by grains of starch, 
which finally often entirely fill up the cell-cavity. Resorption soon 
commences in the two superposed cells; their nuclei lose their sharp 
outline, the cell-walls disappear, and the entire protoplasm has the 
appearance of a homogeneous and refractive mass, the nuclei be- 
coming indistinguishable ; finally the whole substance of these cells 
is absorbed in the development of the lower mother-cell. 

This process is subject to certain variations; but it is always the 
lower cell which becomes the mother-cell, and absorbs the others. 
The starch-grains disappear during the formation of the eight nuclei 
which give rise to the synergide, the oosphere, the antipodal cells, 
and the two polar nuclei which coalesce in order to form the secondary 
nucleus of the embryo-sac. 

In the Cxsalpiniez the apical cell generally gives rise to a thick 
tissue which remains for a considerable time, even after impregnation. 
Variations occur in the subsequent development; and these are 
greater among the Papilionacez, not only in genera of the same tribe, 
but even in species of the same genus. In this order the apical cell 
gives rise only to two superposed cells; the subapical cell remains 
undivided, increases early, and displaces the others. 

As a general result, whatever may be the differences in the origin 
and number of the cells which constitute the axial row of the nucellus, 
it is the inferior cell only which is the true mother-cell of the embryo- 

* Bull. Soc. Bot. France, xxviii. (1881) pp. 197-201. 

+ See this Journal, ii. (1879) p. 903; iii. (1880) pp. 107, 979; i. (1881) pp. 
260, 620. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 65 


sac; there is never any coalescence between two adjoining cells. In 
all the Leguminose the synergide and oosphere, the antipodal cells, 
and the secondary nucleus of the embryo-sac, are formed in the well- 
known mode. The antipodals often disappear after impregnation, in 
consequence of the resorption of the subjacent nucellar tissue. Their 
function, which is still very doubtful, seems to terminate shortly after 
their formation. In other orders of plants, on the contrary, they in- 
crease considerably, even after impregnation. As in the majority of 
Angiosperms, there are no anticlinals, the mother-cell of the embryo- 
sac being the last of the row. 

The presence of two nuclei in one or more cells, as in Cercis, 
does not furnish any real analogy with the special mother-cells of 
pollen-grains, because their division-walls are never completely 
resorbed. 

Antipodals with several nuclei occur in some Ranunculaces, as 
Clematis and Hepatica triloba. The cells are always three in number, 
and are inserted at the base of the embryo-sac, to which they are 
attached by a kind of pedicel. Each of them has a nucleus containing 
at first a single nucleolus. Long before impregnation two nucleoli 
appear (in the hepatica) isolated in the substance of the nucleus; there 
is an internal line of separation between them corresponding to a 
slight depression on the surface, which gradually deepens, and finally 
divides the mother-nucleus into two parts, in which the same pheno- 
menon may then be repeated, though this is not usually the case. 
The whole then presents the form of four segments, in which the 
nucleoli multiply ; and the protoplasm itself may be divided into five, 
six, or even eight rounded fragments. The nucleoli do not elongate 
into an hour-glass form, nor does the substance of the nucleus present 
any median constriction, as is generally the case in fragmentation ; 
they are rather granulations of the nuclear protoplasm, which soon 
attain a considerable size. Finally the mother-nucleus is filled with 
granular nucleoli, and becomes enveloped in the protoplasm. 

There appears, therefore, to be a special process of fragmentation 
in organs whose function is completed, and which may be regarded 
either as an organic residuum or as a degraded prothallium. 


Polyembryony in Mimosex.*—According to L. Guignard, poly- 
embryony is a not uncommon phenomenon in the Mimosee, especially 
in Schranckia uncinata and Mimosa Denhartii, and is allied, in the 
former case, with other abnormalities of structure. 

In S. uncinata the tigellum is furnished, towards its extremity, 
with an appendage of variable form, lobed, and descending below the 
cap which clothes the embryonal radicle. The internal structure of 
this appendage presents several interesting peculiarities. In addition, 
several embryos, formed of an internal normal structural axis, and 
furnished, or not, with this appendage, present three or even four. 
foliaceous cotyledons of equal length folded longitudinally in various 
ways. When the number of cotyledons is three, they occupy the 
angles of an equilateral triangle, and one of them is inserted at a 


* Bull. Soc. Bot. France, xxviii. (1881) pp. 177-9. 
Ser. 2.— Von. II. F 


66 SUMMARY OF CURRENT RESEARCHES RELATING TO 


different level from the others; when the number is four, they are 
arranged in two opposite pairs at different levels. Instead of a single 
tigellum, there are often two of equal size, united in growth during 
the greater part of their length, but distinct towards the base. One 
of these axes occupies the normal position, the other being applied to 
it laterally. 

The appendage is undoubtedly a reserve of food-material. When. 
a seed possessing it germinates, it is exposed along with the radicular 
extremity, increases for some time after the rupture of the testa, then 
gradually loses its starch, which it gives up to the embryo, and finally 
dries up and perishes. 


Resistance of Seeds to extreme Cold.* — E. Wartmann has ex- 
posed fresh-gathered Spanish chestnuts for nearly two hours to a cold 
of at least — 110°, derived from a mixture of sulphuric ether and solid 
carbonic acid, each seed being carefully wrapped in thin tinfoil, so as 
to prevent the surface coming into contact with the ether. The chest- 
nuts were then planted in the soil; they germinated and developed in 
every respect as successfully as those which had not been exposed to 
the cold. The power of resistance to extreme cold appears, indeed, to 
be a very general property of seeds. 


Mechanical Contrivances for the Dispersion of Seeds and 
Fruits.j;—A. Zimmermann has subjected to a fresh examination the 
structure of the seed-vessels of Graminew, Papilionacex, and Gera- 
niacez, by the torsion of which the seeds are buried in the soil, 
especially in relation to the alternate turgidity and desiccation of the 
tissues. His conclusions, which are mainly in accord with those of 
C. and F. Darwin, are as follows :— 

1. The hygroscopic torsion of the awns of Graminez is the result 
of the effort after torsion of the outer cells of the stereome, and of the 
strong contraction of its inner cells, which probably assist by the 
fact that when they swell they assume an oblique position. The 
micella of the former cells are arranged in spiral lines, those of the 
latter in oblique rings. 

2. The effort after torsion of a single spirally striated cell is 
caused by unequal intensity of swelling and unequal firmness in the 
direction of the two systems of rows of micella. The swelling of an 
imaginary cylinder without thickness causes in general a torsion in 
the direction in which there is the strongest swelling. The radial 
swelling of a cylinder possessing thickness, causes, when it is strongest, 
a torsion in its outermost layers in the direction of less firmness; in 
the inner layers, one in an opposite direction. The most probable 
explanation of the fact that a cell in which the most strongly marked 
striations and pores are arranged in spirals inclined obliquely to the 
left, turns itself to the right when it swells, to the left when it dries 
up, is that on the one hand the swelling is strongest in a direction 
vertical to these striations and to that of the pores; on the other 


* Arch. Sci. Phys. et Nat., v. (1881) p. 343. See Naturforscher, xiv. (1881) 
p. 276. 
+ Pringsheim’s Jahrb. wiss. Bot., xii. (1881) pp. 542-77 (8 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 67 


hand, the firmness is greatest in the direction of the rows of micella 
and of the pores. 

3. The cause of the torsion of the legumes of Orobus and 
Caragana resides in the layer of resin, and is brought about in it by 
unequal contraction in the transverse direction, which is indicated 
_by anatomical differences. The outer epidermis (and its anatomical 
strengthening in Caragana) acts only by increasing the strength of 
the mechanism, the vascular bundles of the margin detracting from 
its efficiency. 

4, The torsion of the awns of Geranium is caused by unequal con- 
traction of the cells in the longitudinal direction, these cells manifesting 
also differences in the form and direction of their pores. In the awns 
of Pelargonium the outer strongly developed epidermis effects the 
torsion by strong curvature, the direction of the torsion being ren- 
dered spiral by the tendency to torsion of the inner cells. 

5. The violent expulsion of the seeds of Ovalis is not caused by 
turgidity, but by the energetic swelling of the cell-walls of the trans- 
parent outer layer. 


Chemical Difference between dead and living Protoplasm.— 
The view maintained by O. Loew and T. Bokorny,* that living cells 
are chemically different from dead ones, in that living protoplasm 
shows an aldehyde nature by its power of reducing extremely dilute 
alkaline silver solutions, while dead protoplasm does not, has been 
the subject of an interesting discussion at the Berlin Chemical Society, 
when Herr Reinke denied the chemical difference, and insisted that 
at least a part of the reaction is due to a volatile substance of alde- 
hyde nature which is very frequent in green cells, and which he is 
disposed to regard as formic aldehyde, the first product of assimilation 
of carbonic acid in the plant. 

His opponents urged that they had carefully examined the dis- 
tillation products of various species of Algz and of germs without 
chlorophyll, but had quite failed to find any silver-reducing sub- 
stance. Thinking, further, that they might have been misled by the 
action of sugar or tannin, they convinced themselves that cells reduce 
which have neither of these substances, and a living cell will easily 
reduce a very dilute silver solution which sugar and tannin fail to 
reduce. The intimate relation between silver-reducing power and 
life (in their opinion) is shown clearly by the fact that in whichever 
of many different ways cells of Algz were killed, the reaction in 
question ceased with their death, and precisely at the degree of 
temperature at which life is extinguished. This is generally the case 
in killing by poison; strychnine alone being an exception, which is 
explained by the existence of a combination of the alkaloid with 
molecules of the active albumen. 


Energy of Growth of the Apical Cell and of the youngest 
Segments.j—M. Westermaier commences a dissertation on this subject 
with an historical sketch. Naegeli and Schleiden attributed the causes 


* See this Journal, i. (1881) p. 906. 
+ Pringsheim’s Jahrb. wiss. Bot., xii. (1881) pp. 439-72 (1 pl.). 


F 2 


68 SUMMARY OF CURRENT RESEARCHES RELATING TO 


of the form of any particular part of a plant to the individual cells, 
so that the individual cell plays a prominent part, and the behaviour 
of these determines the form of the organ. A different view is held 
by Hofmeister, Sachs, De Bary, and Hanstein, who regard as the 
primary fact the form of the organ itself, which then determines the 
form and mode of division of the cells. An intermediate position 
between the two is held by Schwendener; the arrangement of the 
cells and the directions of the dividing walls being, according to him, 
determined by two variable factors :—(1) by the individuality of the 
cell; (2) by the form or complete growth of the entire organ, to 
which Schwendener also attributes a share in the arrangement and 
growth of cells. The final position of the walls and arrangement of 
the cells is often also influenced by pressure. 

In order to determine the relative energies of growth of the cells 
of the apical region, the author proposes the following theoretical 
considerations :— 

1. “The apical cell displays the same activity with regard to 
increase in volume during successive stages.” By a stage the author 
means the time which elapses between the formation of a division- 
wall in the apical cell and the formation of the next following 
division-wall. 

2. “The successive segments display an equal activity with 
regard to increase in volume during successive stages.” In this con- 
nection the relationship is investigated between the volume and the 
projection of the lateral profile of a triangular pyramidal and of a 
two-edged apical cell. 

After these theoretical propositions, a comparison is made of the 
energy of growth of the apical cell in Dictyota (according to Naegeli), 
Hypoglossum Leprieurti (Naegeli), Metzgeria furcata (Goebel), Salvinia 
natans (Pringsheim), Equisetum arvense (Cramer), E. scirpoides (Reess), 
and Selaginella Martensii (Pfeffer). 

The general result is stated as follows: —'The maximum of 
increase in volume lies in general either in the apical cell itself or in 
the youngest segments. If we look only at the region which in- 


cludes the apical cell and the four youngest segments, in none of the 


cases mentioned above is the increase of volume least in the apical 
cell. 


Action of Nitrous Oxide on Vegetable Cells.*—Prof. W. Detmer 
has tried a series of experiments on the influence on vegetable tissues 
of nitrous oxide gas, which he states may, to a certain extent, replace 
oxygen in the respiration of plants. For this purpose he took pains 
to obtain the gas absolutely pure, and carefully to exclude every trace 
of atmospheric air. The main results of his experiments, made on 
Triticum vulgare and Pisum sativum, are as follows :— 

1. When grains of wheat or peas are made to swell in water which 
has been boiled and allowed to cool, and then placed for a considerable 
time in contact with pure nitrous oxide, they lose their power of 
germination. 


* SB. Jenaisch. Ges. Med. u. Naturwiss., 1881, July 1. See Bot. Ztg., xxxix. 
(1881) p. 677. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 69 


2. If their contact with the gas is not so long, say from one to 
three days, they do not entirely lose the power of germinating; the 
embryo will begin to develope under normal conditions, 

3. A longer contact with the gas kills the cells. 

4, In a mixture of two parts by measure of nitrous oxide and one 
part of atmospheric air, the power of germination of peas is yery 
greatly weakened. 

5. If peas have been made to germinate under ordinary conditions, 
and then brought into pure nitrous oxide, no further development 
whatever of the root and stem takes place. 

6. In pure nitrous oxide no geotropic or heliotropic curvatures 
take place. 

7. Etiolated parts of plants do not become green in the light if 
surrounded by an atmosphere of pure nitrous oxide. 

8. A number of experiments prove that vitally active cells are not 
able to decompose nitrous oxide; and that they therefore have no 
power of using its oxygen for the purpose of respiration. 


Chlorophyll and the Cell-Nucleus.*—G. Schaarschmidt makes the 
following observations :— 

1. Division of chlorophyll. The mode of division of the 
chlorophyll-grains resembles that of the nucleus, and takes place 
either directly by constriction, or indirectly by division with forma- 
tion of threads. All green chlorophyll-grains divide in one or other 
of these ways, as does also the endochrome of diatoms, as, for example, 
the coccochrome of Odontidium vulgare, and the placochrome of 
Himantidium pectinale. 

2. Hypochlorin occurs also in the Cryptophycee and diatoms. 
When WNostoc, Microcoleus, Merismopedium, and Oscillaria, had been 
treated for two days with concentrated, and then for four days with 
dilute hydrochloric acid, and preserved in it, three, four, or more 
minute rusty-brown masses made their appearance on the surface of 
the cells, which showed the characteristic properties of hypochlorin. 
The endochrome of diatoms treated in the same way becomes dirty 
green, and assumes a spongy structure, hypochlorin appearing at the 
margins in the form of irregular brown masses. This occurred in 
Cymatopleura Solla, Himantidium pectinale, Synedra splendens, Pinnu- 
laria viridis, P. radiosa, &c., and especially in Synedra ulne. The 
reactions were not, however, successful in every individual. 

3. The cell-nucleus of Nostoc. A small round body was observed 
in the cells of Nostoc, usually in contact with the division-walls, and 
which showed beautiful phases in the division of the cells, When 
the cell has elongated and is ready for division, this body parts in 
the middle, a colourless central zone being thus formed in the midst 
of the colouring substance. When oblong cells are placed in coloured 
alcohol-material, the nucleus is constricted ; the constriction becomes 
gradually deeper, and a furrow appears on the outside of the cell. 


* Schaarschmidt, G., ‘ Morphology of Chlorophyll and of the Vegetable Cell- 
nucleus’ (in Magyar); with drawings and a photogram. 56 pp. Klausenburg, 
1881. See Bot. Centralbl., vii. (1881) p. 263. 


70 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Finally the daughter-nuclei divide, and are kept together only by a 
narrow bridge; when the cell-division is complete, these nuclei are 
found again on the division-walls. The diameter of these minute 
bodies is only from 0°5 to 0°6 »; their behaviour when dividing and 
towards colouring reagents is opposed to the view that they are 
chromatin or microsomes. 


Influence of Warmth of the Soil on the Cell-formation of Plants.* 
—RE. Prillieux finds that the effect of warmth in the earth is to cause a 
hypertrophy of the interior of the stem in a young plant; when 
closely examined, this is found to be accompanied by multiplication 
of the cell-nuclei. In the bean and the pumpkin, when the seeds 
have germinated in earth of 10° higher temperature than the surround- 
ing air, cells are often found containing two or three massed or 
isolated nuclei, which may be either equal or unequal in size, and 
of various shapes. This multiplication is effected by fission of the 
nuclei, which generally contain several nucleoli, up to the number of 
four or five, of very different forms and sizes, and sometimes obviously 
constricted preparatory to their division. At the time of division, a 
boundary wall placed either opposite a large nucleus or between two 
closely apposed small ones, divides the nucleus into two halves; these 
two halves swell up, and the whole has usually a kidney-like shape. 
The process is completed by prolongation of the grooves of the surface 
through the dividing wall. 


Growth of Starch-grains by Intussusception.t—In replying to. 


the attack by Schimper{ on the theory of the growth of starch- 
grains by intussusception, C. Naegeli points out that there are three 


different conditions of the “micellar” constitution of the cell-wall 


(using the term “micella” to distinguish the physical ultimate 
elements of a substance from the chemical molecules or atoms) viz. :— 


(1) The living condition of the cell-wall, when it is in immediate. 
contact with living cell-contents; in this condition the cell-wall is. 


more or less strongly coloured by aniline pigments, while the contents 
do not take up any of them. (2) The cell-wall is in a naturally dead 


state when the living contents separate from it, or when they die 


while still remaining in contact with it; in this condition the cell- 
wall does not take up any pigment, while the contents become 
coloured ; and if the cell-wall was coloured when living, it loses its 
colour on passing into the dead state. (38) The swollen condition is 
caused by the action of alkalies or acids, by long boiling in water, 
or by lying for a sufficient time in cold water ; in this state the cell 
wall is again capable of being coloured. 
In every stage of its growth the starch-grain is a material system 
surrounded by a watery fluid, and saturated with water, the tensions 
of which are in a condition of equilibrium. When the grain becomes 
dry, crevices are formed, a proof that the equilibrium is by this means 


* Kosmos, viii. (1881) pp. 63-4. 

+ Bot. Ztg., xxxix. (1881) pp. 633-51, 657-77; also SB. Akad. Wiss. 
- Miinchen, xi. (1881) pp. 391-438. 

¢ See this Journal, i. (1881) p. 909. 


ZOOLOGY AND BOTANY, MICROSCOPY, -ETC. Fé 


destroyed ; and the fissures have a radial direction crossing the layers 
at right angles, a proof that more water is lost in the tangential than 
in the radial direction, and that the total quantity of water deposited 
in the tangential direction is greater. When substances which 
cause artificial swelling act slowly on the naturally saturated starch- 
grain, it increases in volume, radial fissures being again formed, a 
proof that during this process more water is deposited in the radial 
than in the tangential direction. He argues, on mechanical grounds, 
that the tensions found in starch-grains can be accounted for only by 
intussusception, and that these tensions can cause the secretion of 
the soft nucleus and the soft layers only on the supposition that 
intussusception is at the same time taking place. 


Collenchyma.*—H. Ambronn has carefully investigated the his- 
tory of development and the mechanical properties of collenchyma 
in a number of instances, especially in Colocasia esculenta and other 
allied aroids, and in Umbelliferze and Piperacez. 

With regard to the history of its development, these observations 
confirm the statement of Haberlandt that, as in the case of bast, no 
uniform origin can be ascribed to the collenchyma, but that it varies 
in every possible way. Also that the grouping and arrangement of 
the cells is the result, in the first place, of purely mechanical and not 
of morphological laws; and that, when definite relationships exist 
between the collenchyma and the mestome (in Schwendener’s sense of 
the term), these relationships are explained by the history of develop- 
ment. hese relationships occur in those plants in which the origin 
of the collenchyma and of the mestome is uniform, and in those in 
which projecting ridges or angles are produced by the formation of 
vascular bundles at the periphery, groups of collenchymatous cells 
being developed in them in consequence of their centrifugal tendency. 

As regards the structure of the collenchymatous cells, they have 
in general a prosenchymatous character. They are moderately long, 
often 2 mm. or more, and very frequently manifest subsequent seg- 
mentation by delicate division-walls. They are always filled with 
sap, but contain little or no chlorophyll. The longitudinal walls of 
the cells have usually longitudinal crevice-like pores. 

Other collenchymatous cells, on the contrary, have more of a 
parenchymatous character, and: have usually been formed by secondary 
collenchymatous thickening of parenchymatous cells. 

The cell-walls of collenchyma are always coloured a bright blue 
by chlor-iodide of zinc, but are not coloured by the action of phloro- 
glucin and hydrochloric acid. Their power of swelling in water is 
not so strong as has usually been supposed; the cells are seldom 
contracted by more than 4 per cent. of their entire length by the 
application of desiccating reagents. 

The elements of the formative tissue out of which the collenchy- 
matous cells are subsequently developed are partly cambial, partly 
belonging to other meristematic portions. But very often there is 
no special formative tissue; the collenchymatous thickening taking 

* Pringsheim’s Jahrb. wiss. Bot., xii. (1881) pp. 473-541 (6 pls.). 


72 SUMMARY OF CURRENT RESEARCHES RELATING TO 


place only as a secondary result in parenchymatous cortical cells, 
But we have not yet sufficient knowledge to divide collenchymatous 
tissue on this ground into subsections. 

Collenchymatous cells differ in one very essential point from true 
bast-cells. While in the latter the limit of elasticity nearly coincides 
with absolute firmness, in collenchyma the elasticity is overcome by 
a comparatively small strain, the firmness only when the strain is 
increased three or fourfold, 

Since, therefore, a permanent elongation results from the tension 
to which the collenchyma is subjected in the young turgid internodes 
and leaf-stalks, but no rupture, it is clear that this tissue can, in con- 
sequence of its great absolute firmness, afford the necessary assistance 
to the intercalary construction of these organs, without however 
interfering with their growth in length. That the growth in length 
of the collenchyma itself is a consequence of this tension caused by 
the turgidity of the other parts of the tissue, can scarcely be doubted. 
But whether the permanent elongation of the collenchymatous parts, 
caused by the passing of the limit of elasticity, plays any definite 
part in this process, must remain undecided in the present imperfect 
state of our knowledge of the processes of growth in the cell-walls. 


Epidermis of the Pitchers of Sarracenia and Darlingtonia.*— 
Prof. A. Batalin has made a careful anatomical examination of the 
pitchers of Sarracenia flava, purpurea, and variolaris, and Darlingtonia 
californica. He finds that the lower region of the inner epidermis, 
the “detentive surface” of Hooker, has no cuticle; while all the 
other cells of the detentive surface have one, and especially the long 
stiff hairs. The inner region of the pitcher is of a uniform bright- 
green colour within and without; but this is true of the inner surface 
only so long as no insects have been captured ; it then becomes brown, 
the green colour of the outside remaining. While on the green spots 
on the inside of the pitcher the moderately thick and nearly colour- 
less outer walls of the epidermal cells are quite smooth, at the brown 
spots, where insects have come into contact with them, they have one 
or more irregular spots of a much lighter colour. Treatment with 
chlor-iodide of zinc causes these spots, but not the rest of the cell- 
walls, to turn blue. 

This observation leads to the conclusion that the contact of an 
insect with the epidermal cells causes a change in the latter, which 
consists chiefly in the exeretion, between the cuticle and the cellulose- 
wall, of a fluid, the nature of which has not been determined, but 
which probably has the property of dissolving albuminoids. It 
appears to act both mechanically and chemically upon the cuticle, 
forcing it outwards, and finally rupturing and almost entirely destroy- 
ing it. A change is at the same time taking place in the cellulose- 
wall. It assumes a brown colour, and in addition becomes partially 
mucilaginous. 

The author also describes a peculiar sieve-like disk between the 
epidermis and the glands of Pinguicula vulgaris. 

* Acta Hort. Petrop., vii. (1880) pp. 343-60 (1 pl.). See Bot. Centralbl., vii. 
(1881) p. 327. 


- 
a 
r 
& 
cs 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 73 


Laticiferous Vessels.*—D. H. Scott has investigated the struc- 
ture and development of the laticiferous vessels, chiefly in Tragopogon 
eriospermus ; also in Scorzonera hispanica, Taraxacum officinale, and 
Chelidonium majus. The following are the most important results :— 

The laticiferous vessels are developed out of rows of cells, the 
transverse walls of which have been gradually absorbed, and, when 
two vessels lie side by side, the lateral walls also partially. The 
resorption usually takes place at an early period; in seedlings during 
the first stages of germination; in the secondary cortex shortly after 
the cells in question have separated from the cambium. 

The connection between distant laticiferous vessels is brought 
about in two ways; either by rows of cells that run transversely 
coalescing with one another, or by protuberances which unite in their 
growth, and which finally form canals similar to those of the Conjugate. 

Even before the first septa are absorbed, the cells are characterized 
by special contents, of which latex is probably a constituent. 


Epidermal System of Roots.j—L. Olivier has made a careful 
study of the epidermal tissue in the roots of Vascular Cryptogams, 
Gymnosperms, Monocotyledons, and Dicotyledons, dividing the latter 
into two classes, those in which- the secondary vascular system 
originates early, and those in which it originates late. The following 
are the general results :-— 

The piliferous layer of the root does not correspond to the 
epidermis of the stem, but rather to one of its hypodermal layers. It 
is this which gives birth to the “ veil,’ a system of layers of cells 
proceeding from the piliferous layer; as it peels off, the subjacent or 
epidermoidal layer most generally assumes the anatomical character 
of the epidermis, and the same physiological functions. 

The secondary tissue of the epidermal system of the root is 
either parenchymatous or of a corky nature. The secondary epidermal 
parenchyma proceeds from a peripheral layer of the central cylinder; 
it attains considerable development in Dicotyledons with early secon- 
dary vessels, and in Gymnosperms; there is none in Vascular Cryp- 
togams, in the great part of Monocotyledons, nor in Dicotyledons with 
late secondary vessels. 

In Gymnosperms and in Dicotyledons with deciduous primary 
bark, the cork is derived from the pericambial layer. It is composed 
of tabular cells, the radial walls of which are very short. 

In woody Dicotyledons with late secondary vessels, in Monocoty- 
ledons, and in Vascular Cryptogams, the production of cork takes 
place in the external zone of the cortical parenchyma; the cork is 
here composed of cubical cells. 

In any particular species, the zone of the root where the cork 
appears depends on the transverse diameter of the organ, and on its 
physical surroundings. The diameter being the same, the cork is 
generally earlier and more abundant in the aerial than in the under- 

_ground roots. 
* Scott, D. H., ‘ Zur Entwickelungsgeschichte der gegliederten Milchrohren 


der Pflanzen.’ Inaugural Dissertation. 23 pp. Wiirzburg, 1881, 
¢ Ann. Sci. Nat. Bot., xi. (1881) pp. 5-129 (8 pls-). 


74 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Passage from the Root to the Stem,*—R. Gérard concludes 
from a careful examination of the facts connected with this subject 
that a “collar” does not exist as a geometrical expression. Between 
the root and the stem is a region, more or less extensive, where the 
elements of the root, advancing to the higher parts of the axis, become 
modified, gradually assuming the configuration, place, and importance 
which they possess in the stem. The transformation of each of the 
elements is independent of that of its neighbours, and may take place 
slowly or very rapidly. Hence the collar, considered anatomically 
from different points of view, presents the most variable aspects. The 
transformation of the epidermal system furnishes no guide to the 
limitation of stem and root; the change in the epidermis is one of the 
phases of the passage. 

Using the term in its widest sense, the collar may commence in 
the upper part of the radicle and extend to the fourth internode, rarely 
passing the cotyledons, or it may be entirely localized in the radicle ; 
it may occupy a part of the organ, and the whole or a part of the 
tigellum. Most often the passage is completely effected in the tigel- 
lum. The size of the collar is in proportion to the diameter of the 

lant. 
. No family characters can be drawn from the study of the collar; 
its peculiarities are constant only in the species. It is connected 
with the accommodation of the plant to its surrounding conditions. 


Causes of Eccentric Growthj— Dr. E. Detlefsen has investi- 
gated the cause of eccentric growth in thickness of woody stems and 
roots in a number of instances, and finds it attributable to the four 
following causes :— 

1. Branches and axillary roots cause, at the point from which they 
spring, a diminution of the tension of the bark, and consequently an 
acceleration of the growth in thickness, which is most considerable 
where the surface of the lateral organ forms the smallest angle with 
that of the mother-organ. 

2. Every diminution or increase in the tension of the bark is 
perceptible over a large extent in the longitudinal direction of the 
bast-fibres. 

3. Every lateral pressure which causes curvature of the organs 
brings about an increase in the tension of the bark on the side which 
becomes convex, a diminution on that which becomes concave. 

4, Convex surfaces cause an increase, concave surfaces a decrease, 
in the tension of the bark, which affects chiefly the different sides of 
curved branches and roots. 

These influences may be exercised either in conjunction or sepa- 
rately. 


Hydrotropism of Roots.{ — The term “hydrotropism” has been 
suggested for the tendency displayed by roots, when placed between a 


* Ann. Sci. Nat. (Bot.,) xi. (1881) pp. 277-430. 

+ Detlefsen, E., ‘ Versuch einer mechanischen Erklirung des excentrischen 
Dickenwachsthums verholzter Achsen u. Wurzeln.’ 13 pp. (1 pl.) Weimar, 1881. 

+ Bull. Soc. Bot. France, xxviii. (1881) pp. 115-21. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 75 


moist and a drier medium, to direct themselves towards the former, to 
an extent often sufficient to overbalance geotropism. As the resul’ of 
a series of observations, M. Mer contests the view that hydrotropism ‘s 
a special instinctive faculty of the root; he attributes the phenomeno 
to the retardation of growth consequent on an insufficient supply of 
moisture, a condition which may completely prevent the manifestation 
of geotropism. 


Cause of the Swelling of Root-fibres.*—E. Mer and M. Cornu 
have observed that when the roots of growing plants are placed in 
coloured fluids, if the solution is too concentrated so as to check 
growth, each root-fibre swells near the apex, the swelling being often 
accompanied by a more or less decided curvature. M. Cornu attri- 
butes this phenomenon to the same cause as the swellings caused by 
-phylloxera and by gall-insects, viz. not the special influence of a 
particular fluid, but tensions developed locally by any cause, and in 
many cases the arrest of development of an organ in course of 
elongation ; the production of a fluid may, however, in certain cases 
co-operate with this. 


Frank’s Diseases of Plants—The completion of this work, to 
the publication of the lst part of which we have already alluded,t 
furnishes a very complete account of the various diseases and injuries 
to which plants are subject. It is divided into five sections, as 
follows:—1. The living and dead state of the vegetable cell. 2. 
Action of mechanical influences. 3. Diseases caused by influences of 
inorganic nature. 4. Diseases caused by other plants. 5. Diseases 
caused by animals. . 

Under the first head the author describes the phenomenon known 
as the “apostrophe” of the chlorophyll-grains. The normal position 
of the chlorophyll-grains he states to be in a layer especially next to 
those parts of the cell-wall which are not in contact with adjacent 
cells—on the outer side, therefore, of epidermal cells, and on walls 
that border intercellular spaces; and to this position he applies the 
term epistrophe. Certain unfavourable influences, as long-continued 
absence of light, wounds, &c., cause the chlorophyll-grains to lose 
this position, and group themselves along those cell-walls that are 
- in contact with other cells; and this abnormal position he calls 
apostrophe. 

The production of wens is thus described. The first cause is 
always a small wound in the periderm, which sometimes appears to be 
a crevice over a lenticel. Between the dried margins of the outer 
ruptured cortical layer there then projects a living new formation in 
the form of a light-brown cushion, which is either a round tuber or a 
long wheal, according to the shape of the wound; a cluster of smaller 
tubers often break out in addition from the bottom of the wound. 
When this cushion projects to a height of 1 mm. above the wound, 
it consists only of cortex and bast, not of wood; it is a hypertrophe 
of the cortex, enclosed in a young periderm. The parenchymatous 


* Bull. Soc. Bot. France, xxviii. (1881) pp. 124-7. 
+ See this Journal, i, (1881) p. 273. 


76 SUMMARY OF CURRENT RESEARCHES RELATING TO 


tissues of the cortex and bast form the greater part of this cushion. 
At its base and in the neighbourhood of the bast of the stem is a hard, 
horny tissue, consisting of extremely thick-walled cells, resembling 
the bast-fibres, but short, also nearly iso-diametric, also of sclerenchy- 
matous cells of great size, their cell-walls so greatly thickened that 
the cavity has nearly disappeared, and with pit-canals. At a later 
stage the woody tissue is also enclosed in the hypertrophy. Nothing 
is said by the author about adventitious buds, 

Among parasitic fungi causing diseases of plants, Frank includes 
species of Chytridiacer, Saprolegniacee, Peronosporee, Ustilaginer, 
Urediner, Hymenomycetes, Discomycetes, and Pyrenomycetes; and 
describes the following new species, viz.:—Saprolegnia Schachtii, on 
Pellia epiphylla; Ramularia Vicie, on Vicia tenuifolia ; Cercospora 
Phyteumatis, on Phyteuma spicatum; and Gleosporium Phegopteridis, 
on Phegopteris polypodioides. The mycelium of Agaricus melleus he 
regards as the cause of the extensive vine-disease known in France as 
“plane des racines.” The sclerotial disease of rape-seed is caused by 
Peziza sclerotioides; and that of Impatiens glandulifera and other 
species of Balsaminee by a fungus to which Frank gives the provi- 
sional name Sclerotium Balsamine. The lowest internodes of the 
stem lose their turgidity, become flaccid, and look as if they had been 
boiled ; and the plant quickly dies. The tissue is penetrated by a 
mycelium on which are small black sclerotia. | 

A full account is given of the production of galls by Phytoptus 
and other gall-producing insects, The following description is given 
of the formation of the bag-shaped galls on the leaves of Prunus 
Padus. The insect probably in the first instance inflicts injuries 
which excite the production of the galls; but they only retreat into 
the galls at a later period when the care for their offspring comes 
into play. 'The same appears to be the case with Erineum tiliacewm. 
The insect could not be detected either at the spot where the injury 
is first made, or in the immature gall; not till the beginning of 
June, when they are found in abundance, with their eggs, in the galls. 
In the case of the lime the injury appears to act on both sides of the 
leaf, 


B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 


Prothallium and Embryo of Azolla.*—Prof. 8. Berggren has 
followed out carefully the development of the prothallium and embryo 
of Azolla caroliniana. 

As in Salvinia the endospore splits, on germination, along its 
three edges. On escaping, the prothallium has the form of a slightly 
convex disk, consisting in the middle of several layers of cells, at the 
margin of only one, and separated below by a thin hyaline membrane 
from the large protoplasmic spore-cavity. Shortly afterwards an arche- 
gonium is formed near its centre, consisting of four cells enclosing the 
oosphere and of four neck-cells. If this archegonium is fertilized, no 


* Lunds Univ. Arsskrift., xvi.; and Rey. Sci. Nat., i. (1881) pp. 21-31 (1 pl.). 


ee 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. (7 


others are usually formed, but if not a few others are subsequently 
developed. When quite mature the part of the prothallium which 
projects outside the spore is nearly hemispherical, and three obscure 
wings are produced by three longitudinal furrows. The cells contain 
chlorophyll. 

The position of the oosphere with respect to the neck of the 
archegonium probably corresponds to that in Salvinia. After fertiliza- 
tion itis divided by the first oblique division-wall into a smaller upper 
cell facing the neck of the archegonium, and a somewhat larger lower 
cell filled with coarsely granular protoplasm. By successive walls 
vertical to one another and to the first division-wall, and parallel to 
its longitudinal axis, the embryo is then divided into octants. In each 
octant a wall next appears parallel to the first division-wall; and the 
entire embryo then consists of 16 cells, arranged in four parallel 
rows. : 

The four cells which lie at the upper pole are the rudiment of the 
foot. Of the four lowermost cells one is the origin of the apex of the 
stem, another developes into an organ resembling the first leaves, the 
two others are together the rudiment of the scutellum. In its sub- 
sequent growth the young apex of the stem follows the ordinary laws ; 
only the bud is at first straight, and the characteristic curving upward 
of the cone of growth is a subsequent phenomenon. The leaves first 
produced are strongly concave, and, in contrast to the later ones, are 
not lobed. Some of the hairs which mark the upper side of the apex 
of the stem are formed at the same time as the first leaf. The scu- 
tellum originally encloses the bud as a crescent-shaped growth, the 
margins of which gradually approach until it encloses it like a 
sheath. The leaf-like organ resulting from the second cell of the 
lower pole of the embryo is at first, like the scutellum, independent 
of the apex of the stem, and morphologically equivalent to it. Neither 
can therefore accurately be termed aleaf. The first vascular bundle 
of the plant is formed at an early period by tangential walls in the 
eight cells which compose the centre of the embryo. 

After fertilization the embryo turns, as in Salvinia, within the 
archegonium, so that the apex of the stem is turned towards that of 
the prothallium. The embryo breaks through the prothallium near 
the archegonium, and the prothallium then surrounds the foot of the 
embryo like a cup, carrying the withered archegonium on its dorsal 
side behind the scutellum. 

To prepare for fertilization, the massule of the microsporangia, 
with their anchor-shaped glochidia, fix themselves in large numbers 
to the under epispore of the macrospores which are floating on the ~ 
‘surface of the water. The central fibrous portion of the floating 
apparatus is perforated by a narrow canal, through which the anthe- 
rozoids probably reach the archegonium. By their subsequent growth 
‘the prothallium, and later also the embryo, force themselves into this 
canal, and increase its size. By this means the three floating bodies 
are displaced from their original position, and finally stand at a right- 
angle from the macrospore. The indusium which covers the floating 
apparatus in the form of a brown cup is at the same time pushed 


78 SUMMARY OF CURRENT RESEARCHES RELATING TO 


upwards, and finally forced against the embryo. The hood-like 
fibrous layer which is closely applied to the floating apparatus, is 
turned over, and surrounds the foot of the embryo like a collar. 
Shortly afterwards the embryo detaches itself from the macrospore ; 
the margins of the scutellum become broader, and then lie on the 
surface of the water in the form of eups or scales. 

The strongly refractive bodies previously observed by others 
between the indusium and epispore, are, according to the author, 
Nostoc-cells, which find their way into the crevices between the scu- 
tellum and the young leaves when the apex of the embryo appears 
outside the epispore. 


Development of the Sporangia and Spores of Isoetes.*—On the 
disputed point whether the sporangia of Iscetes spring from super- 
ficial or from deeper lying cells, E. Mer considers that he has 
demonstrated the latter from the case of sterile leaves which are the 
result of the abortion of the sporangia at various stages. 

In the earliest stage of development of the sporangium, while the 
leaves are still in vernation, it is not connected with the leaf by a 
pedicel; the tissue is, on the contrary, homogeneous, composed of 
young, very delicate, polyhedral cells, with no trace of trabecule or 
envelope. The pedicel is afterwards formed by expansion of the 
lateral parts. The cells of which it is composed differ from those of 
the rest of the organ ; they are elongated horizontally, are polyhedral, 
with very acute angles, and enclose starch. ‘The macrosporangia and 
microsporangia can be distinguished even at this period. Among the 
cells of the macrosporangium appear radiating rows of cells, similar 
to those of the pedicel, which are the young trabecule ; the external 
envelope becoming at the same time differentiated. 

In the second stage the mother-cells of the macrospores increase 
in size, and contain vacuoles, growing at the expense of other cells 
which decrease in size and at length entirely disappear. The 
nutritive tissue is finally confined to one or two rows of cells situated 
at each side of the trabecule, which no longer contain starch, 

In the third and final stage the mother-cells of the macrospores 
divide into tetrahedra; the macrospores become isolated, and float in 
the empty space between the trabecule. The mother-cells of the 
microspores cannot be made out till a later period than is the case 
with the macrospores. 

In the primitive meristem, from which are developed the macro- 
and microsporangia, three tissues are speedily differentiated: viz. a 
formative tissue destined to produce the mother-cells; a nutritive 
nitrogenous tissue, which is absorbed at the expense of the mother- 
cells; and an amylaceous nutritive tissue intended to supply the 
mother-cells with nutriment. 

M. Mer found that the supply of food-material caused a re- 
markable difference in the development of Isoetes lacustris, of which 
he accordingly distinguishes four forms. An abundant supply of 
food is necessary for the formation of the macrosporangia, an 


* Bull. Soc. Bot. France, xxxviii. (1881) pp. 72-6, 109-13. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 79 


insufficient supply promoting the production of microsporangia. 
The dissemination of the macrospores extends over a longer period 
than that of the microspores. The bulbils correspond in this respect 
to the macrospor-s. 


Muscinee. 


New Genera of Mosses.*—C. Miller describes four new genera 
of mosses :—Wilsoniella, belonging to Bryacez, one species from 
Ceylon, and another from Australia; Thiemia, belonging to Funa- 
riacex, one species from Burmah; Rehmanniella, belonging to Pot- 
tiaceze, one species from South Africa; and Hampeella, belonging to 
Hookeriacee, one species from Java. 


Classification of Sphagnacese,t—C. G. Limpricht lays consider- 
able stress, in the determination of species of Sphagnum, on the 
~ relative position of the chlorophyllaceous and the hyaline cells in the 
leaves of the branches, a character which he considers has been too 
much neglected by Warnstoff in his recent synopsis of the group.} 
Limpricht reunites S. subbicolor Hampe and S. glaucum vy. Klinger. 
to S. cymbifolium. 


Characee. 


Cell-nucleus in Chara foetida, §—F. Johow has made an extensive 
series of observations on the changes which take place in the nucleus 
in cell-division in Chara fetida, for the purpose of determining the 
correctness on the one hand of Schmitz’s description of it as “ direct 
division of the nucleus,’ || or that by Treub and Strasburger as 
“fragmentation.” For this purpose he used chiefly the apical cells 
and primary segment-cells of the stem, those of the so-called “ pro- 
embryo,” of the leaves and cortical lobes, and of the nodes, employ- 
ing the methods of hardening and colouring by means of picric acid 
and hematoxylin. 

The results obtained were in many respects different from those 
previously described by Schmitz, Treub, and Strasburger, a difference 
which the author suggests may be explained by the fact that the 
various observers have had under observation different species or 
varieties of Chara. The “fragmentation” which Strasburger de- 
scribes was also not observed by Johow in the staminal hairs of 
Tradescantia, the parenchymatous cells of Nicotiana and Tropeolum, 
or the suspensor of Orobus. The following are the chief points on 
which he insists. . 

The cell-nucleus of Chara fotida retains the same structure in 
essential points throughout its existence, viz. a homogenous matrix 
in which are imbedded chromatin-particles of varying number and 
form; the occurrence of the nuclear wall is not limited to any par- 
ticular stage. A disorganization of the cell-nucleus did not accom- 


* Bot. Centralbl., vii. (1881) pp. 345-9. 

¢ Ibid., pp. 311-19. 

{ See this Journal, i. (1881) p. 773. 

§ Bot. Ztg., xxxix. (1881) pp. 729-43, 745-53 (1 pl.). 
|| See this Journal, i. (1881) p. 475. ; 


80 SUMMARY OF CURRENT RESEARCHES RELATING TO 


pany or follow the fragmentation; on the contrary, the multiplication 
of the nuclei was accompanied by a considerable increase in size of 
the chromatin-particles and of the matrix. The same was the case 
with the cell-nucleus of Phanerogams. The division of the nucleus 
in the cell-division of Chara fotida is completed in a manner very 
different from the later multiplication of nuclei, and presents also 
but little resemblance to the mode of division in most animals and 
plants. But in the older nuclei there is a considerable series of tran- 
sitional forms in the same plant, to the most simple mode of division 
by means of external constriction of the nuclear mass without internal 
differentiation. 

There appears to be no essential morphological distinction between 
karyokinetic division and fragmentation. 


Fungi. 
Conidial Apparatus in Hydnum.*—Ch. Richon describes what — 
he considers to be a hitherto undetected reproductive apparatus 
in Hydnum erinaceum. It resembles that described by M. Cornu in 
Ptychogaster albus, and consists of intracellular conidia in the paren- 
chyma, situated in the superior zone of the receptacle, and prolonged 
into the median zone. Instead of being produced at the extremity of 
cells of the parenchyma, they are formed and develope in the interior 
of the cells. They vary in size from 6-7 p in diameter, being usually 
ovoid, less often rod-shaped. Conidia of somewhat similar origin 
are found in Fistulina hepatica, Polyporus sulfureus, and Corticium 
dubium. 


Alternation of Generations in Uredineew.t—E. Rathay confirms 
Winter’s observation that the Cwomata, on roses, potentillas, and the 
raspberry, are the ecidial forms of Phragmidia ; he found spermogonia 
on them. The test of an ecidial form he considers to be not the 
envelope or the chain of spores, but the presence of spermogonia. 
He regards Melampsora populina and Aicidium Clematidis as 
probably developmental forms of the same species. 


Mode of Parasitism of Puccinia Malvacearum.t—The mode in 
which the germinating filaments from the sporidia of Puccinia Malva- 
cearum penetrate the host has been variously stated to be through the 
stomata, and through the cuticle where the lateral join the superficial 
cell-walls. E. Rathay finds that though the latter is often the case, 
they frequently perforate the epidermal cells at a point distant from 
any lateral wall. 


Sterigmatocystis.§ —Cramer first described this genus of fungi 
from S. antacustica, found in the ear of a deaf person. M. Bainier 
now gives the characters of six new species:—S. usta, ochracea, 


* Bull. Soc. Bot. France, xxviii. (1881) pp. 179-82 (1 pl.). 

+ Verhandl. zool.-bot. Ges. Wien, Jan. 5, 1881. See Bot. Centralbl., vii. 
(1881) p. 164. 

{ Verhandl. zool.-bot. Ges. Wien, Dec. 1, 1880, See Bot. Centralbl., vii. 


(1881) p. 163. sae 
§ Bull. Soc. Bot. France, xxviii, (1881) pp. 76-9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 81 


quercina, aerea, Helva, and fuliginosa. They are found on all sorts of 
ternary compounds, starch, dextrine, sugar, paper, tannin, &c., and 
may be cultivated on gelatine, gluten, and bread, but not apparently 
on meat. They are extremely abundant on grapes, and on other 
edible commodities, the species being especially S. nigra, carbonaria, 
and fuliginosa, while S. glauca is found in wine. Glycerin is ex- 
tremely prejudicial to their growth, and may be used to prevent 
their appearance. The spores have a great power of resistance to 
cold; and, when once established, these moulds are very difficult to 
extirpate. 


Oospores of Phytophthora infestans.*—M. Cornu has reinvesti- 
gated the vexed question of the oospores of Phytophthora (Pero- 
nospora) infestans, which have not yet been recognized with certainty. 
The bodies described by W. G. Smith as the sexual spores of the 
_ Phytophthora, Cornu agrees with de Bary in regarding as in reality 
the oospores of a Pythium. Caspary and Berkeley, on the other hand, 
regarded as the true oospores of Phytophthora the bodies described by 
Montagne under the name Artotrogus hydnosporus, a conclusion 
doubted by de Bary on the ground of their alleged identity with 
similar bodies found on the turnip. Cornu shows, however, that this 
latter parasite is altogether different from that of the turnip. The 
bodies described as Artotrogus are of two kinds, one echinated, the 
other not. The former of these Cornu considers in all probability to — 
be the oospores either of Phytophthora, or of some Saprolegnia at 
present unknown. 


Peronospora viticola.j—E. Prillieux, after pointing out the 
known existence of conidia or summer-spores, and oospores or winter- 
spores, states that he has been able to convince himself, during the 
course of a mission undertaken under the instructions of the Minister 
of Agriculture, that there is no doubt as to the “ prodigiously 
abundant formation of winter-spores” in various parts of Trance. 
The quantity of these small bodies which may be found in one dry 
leaf appears to be enormous (200 per square millimetre). Not 
much harm is done in dry weather, but when the seasons are wet 
me author thinks that all the vine-leaves should be collected and 

urnt. 


Vegetation of Fungi in Oil.t—P. Van Tieghem some years since 
observed the development of flakes of mycelium in a bottle of olive 
oil; this was due to two germs; one not cultivable on slices of 
potato, the other identified as very nearly allied to Verticilliwm cin- 
nabarinum. Immersion of seeds or pieces of the higher plants, 
covered with mycelium growth, in the same medium, and placing in 
an atmosphere at about 25° C., produced after a few days a plentiful 
growth of mycelium over these bodies, on the surface of the oil, and 
at any points at which spores had been left in contact with the air. 
It is established that the oil is absolutely necessary to the life of the. 

* Bull. Soc. Bot. France, xxviii. (1881) pp. 102-9. 
+ Comptes Rendus, xciii. (1881) pp. 752-3. 
t Bull. Soc, Bot. France, xxvii. (1880) p. 353. 
Ser. 2.—Vot, II. G 


82 SUMMARY OF CURRENT RESEARCHES RELATING TO 


fungus; it will not develope in linseed oil, colza oil, or water, and 
is killed if transferred from olive oil to any of these liquids. If the 
mycelium is removed from the plants before being transferred to the 
oil, its development is very slow, and fructification is not obtained; 
this is probably due to the want of the water which the plant 
contained. The systematic position of the form could not be 
determined. 

He also finds as the result of subsequent investigations* that a number 
of mycelia flourish in a variety of oils, as those of olive, poppy, linseed, 
and colza, and in castor-oil. Most of these are still undetermined, 
and one appears to be a species of Verticillium. Among those which 
appeared in olive-oil is a new Saccharomyces, to which he gives the 
name S. olei. It consists of oval cells arranged in branched threads, 
which occasionally become broken up, and the isolated cells then bud 
and form new threads. The average size of the cells is 4:0 pw by 
2°51; their contents of a pale or, in refracted light, of a slight rose 
colour. No disengagement of gas, or special odour, accompanies their 
growth. At length they form a farinaceous deposit at the bottom of 
the water. The nature of the oil is completely changed in the 
process, becoming white and milky in the course of about eight days. 
Neither S. cerevisie nor any other allied species will grow in 
olive-oil. 

A moneron grown in the same way in castor-oil developed through 
the whole substance of the oil, rendering it opaline; it does not, 
however, change its nature or saponify. 

If into any oil that has not been purified any body is introduced 
which has been soaked in water, the surface of the body is seen, after 
a few days, to be covered with an abundant vegetation, composed of 
the mycelia of a number of fungi, among which have been detected 
Mucor spinosus and pleurocystis, and species of Verticillium, Cheeto- 
mium, and Sterigmatocystis, but most abundantly of all, Penicillium 
glaucum, which fructifies profusely, not only on the surface, as is the 
case with aqueous solutions, but throughout the oil. Other Asco- 
mycetes produce not only their conidia, but also their perithecia in 
these conditions. These fungi are produced ina great variety of un- 
purified oils, but not in an oil which has been purified by sulphuric 
acid like colza-oil, or which has been strongly heated, like linseed- 
oil. If the moist substance is placed for a time in boiling water 
before its immersion in the oil, it still becomes covered after a time 
with the fungoid growth, showing that the spores are in the oil and 
not in the moist substance ; the reason for their not developing in the 
oil, if left to itself, being that water is necessary for their growth. 
The plant obtains its necessary oxygen and nitrogen from the air dis- 
solved in the oil; the oil itself furnishing direct to the plant the 
carbon and the hydrogen. A sufficient quantity of nitrogenous and 
mineral substances is always contained in unpurified oil. The oil 
remains perfectly limpid, and apparently does not undergo any change 
in composition, except a crystallization of fatty acids, indicating a slow 
saponification. 


* Bull, Soc. Bot. France, xxviii. (1881) pp. 70-1, 137-42. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 83 


Parasitic Fungi.*—M. Cornu notices the occurrence of two para- 
sitic fungi on hosts not previously observed, Cylindrospora nivea on 
Veronica arvensis, and a uredo, probably belonging to the cycle of 
generation of Acidium nitens, on an unnamed American Rubus. 


Ear-Fungi.t—Fr. Betzold has detected the following species of 
Hyphomycetes as accompaniments of diseases of the ear, viz. Asper- 
gillus nigricans, flavescens, and fumigatus, and Trichothecium roseum. 
He does not regard these fungi as saprophytes, but as the actual cause 
of inflammation. 

Insect-destroying Cryptogam.j—-J. Lichtenstein calls attention 
to a very curious case of parasitism, namely, the presence in the hot- 
houses of the Jardin des Plantes, at Montpellier, of an “insecticide 
eryptogam ” (a Botrytis), which killed all the aphides on a 
Cineraria. 

The action of the parasite would appear to cease in the open air, 
at least the author was unable to inoculate with it either the 
Phylloxera or an Aphis (Chaitophorus aceris). Perhaps, the author 
speculates, direct inoculation is impracticable, and there may exist an 
intermediate stage on other creatures, as in Hntomophthora and cine 
Cryptogams. 


Brefeld’s Schimmelpilze.§—The fourth part of O. Brefeld’s general 
work on mycology treats of the moulds or Schimmelpilze, and is 
introduced by some general remarks on the cultivation of microscopic 
fungi. He especially recommends the use of Geissler’s modification 
of Recklinghausen’s chamber, which has special advantages for the 
culture of single specimens. 

The life-history of Bacillus subtilis is described in detail, followed 
by that of Chetocladium Fresenianum, parasitic upon Mucor and 
Rhizopus, but which will readily grow in nutrient fluids, and can 
easily be made to produce zygospores. Two new species of 
Thamnidium, and one of Mucor, are also described. He regards as 
_ the ancestor of the Zygomycetes a form with one kind of sporangium, 

from which sprang the Thamnidiez with sporangia and sporangioles. 
Thence were derived various branches:—by the reversion of the 
sporangioles to forms with single conidia; by the separation of the 
sporangioles and conidia to separate receptacles, to the Choanephoree ; 
by the abortion of the sporangia to the Cheetocladiacez. 

Under the head of Pilobolus, a special description is given of 
P. anomalus, in which large portions of the mycelium, divided off by 
septa, produce each a receptacle ; a division in the young sporangium 
after the formation of the columella leads to the production of the 
sporiferous portion and the swelling-layer, which, after first becoming 
dry, then absorbs water, swells up, and separates the sporangium from 
the pedicel. The author has, in this species, observed germinating 


* Bull. Soc. Bot. France, xxviii. (1881) pp. 143-6. 

+ ‘Zur Aetiologie der Infectionskrankheiten,’ 1880, pp. 95-109. 

{ Comptes Rendus, xelii. (1881). 

§ Brefeld, O., ‘Unters. aus dem Gesammtgebiet der Mykologie. Heft 4. 
Bot. Unters. iiber Schimmelpilze.” 191 pp. (0 pls.). Leipzig, 1881. 


Gg 2 


84 SUMMARY OF CURRENT RESEARCHES RELATING TO 


zygospores in the ordinary receptacles. Very different is the origin 
of the receptacle in five other species of Pilobolus, in which only a 
single short tuberous piece is divided off from the mycelium by a 
septum, the receptacle being produced entirely in this. The energy 
of the process by which the spores are thrown out is in inverse pro- 
portion to the length of the pedicel. The author was unable to find 
zygospores in these species, and believes the sexual mode of repro- 
duction to have fallen, with them, partially into abeyance. The 
production of the receptacle of Pilobolus is greatly dependent on 
light. 

Descriptions follow of other Zygomycetes, Sporodinia grandis and 
Mortierella Rostafinskii, the latter of which is found on horse-dung. 
The short mucor-like receptacles are formed on short stolons, and are 
usually fixed to the substratum by thick bundles of rhizoids at the 
base of the receptacle, often enveloping it, and thus forming a tissue 
composed of unseptated filaments, resembling a capsule, and about 
one-fourth the height of the receptacle, the sporangium being exserted 
from itsapex. The outer portions of this structure are of a yellowish 
or brownish colour, and are cuticularized, the sporangia remaining 
white even when mature. The sporangia are not produced from the 
entire apex of the fertile hyphz, but only from a small central zone, a 
peculiar constriction being formed beneath them. When the spores 
have been formed out of the protoplasm, a division-wall separates the 
sporangium from the pedicel without the formation of a columella. 
As the spores are developing, the walls of the upper part of the 
pedicel become thicker, as also does the basal part of the wall of the 
sporangium, which remains behind like a collar when the upper part 
has become separated and the spores have escaped. In old cultures, 
or those which have been disturbed, gemmz often made their appear- 
ance, as in Mucor racemosus. In very poor nutrient fluids, the number 
of spores was reduced from many thousands to two or four, and the 
rhizoids were entirely wanting. After long-continued culture, and 
the succession of from ten to twelve generations, the production of 
non-sexual receptacles almost entirely ceased, and zygospores only 
were produced, enclosed in large brown capsular tissues. In other 
instances, however, this envelope was wanting. 

The nature of the sporangium and the conidia derived from it are 
used by Brefeld as the foundation of the classification of the Zygo- 
mycetes, which he divides into five families, viz. Mucorinex, 
Thamnidiez, Choanephorex, Cheetocladiacexe, and Piptocephalidez. 

In Entomophthora radicans, Brefeld describes the formation of the 
resting-spores, from which he concludes that the Entomophthorez 
form a small family more nearly allied to the Ustilaginee than to the 
Peronosporex, being most nearly connected with the former through 
Entyloma. In both families he considers the resting-spores to be 
oogonia, in which the formation of spores is suppressed, and the 
oogonium itself has become a spore. Their natural position is 
therefore in the Oomycetes, near to the Phycomycetes. Two new 
species of Empusa are described, one parasitic on flies, the other on 


,. gnats. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 85 


The formation of both conidia and sclerotia is followed out with 
care in Peziza tuberosa and sclerotiorum, and the view is confirmed 
that there is no causal connection between the two. The sclerotia 
always proceed from a mass of hyphze which put out abundance of 
shoots, and are more slender than other mycelial filaments. As soon 
as they begin to coil and interweave, a general lateral branching takes 
place, which gradually fills up all the air-cavities in the ball, and 
unites the hyphz with one another. The sclerotia retain their power 
of germination for years, if kept dry. They then put out thick 
greyish-yellow club-shaped bodies composed of nothing but hyphe, 
which grow by apical growth and finally become the fertile cups, the 
apical growth ceasing at the middle, while the peripheral filaments 
continue to grow and branch abundantly. After growth in length has 
ceased, a layer of paraphyses is formed gradually from the middle 
towards the margin, the asci being then formed, their formation con- 
tinuing after the expulsion of the first spores. The ascospores, eight 
of which are contained in each ascus, are 8 » broad and 12 p long. 
They germinate at once, and form ordinary mycelia with sclerotia. 
In the autumn the club-shaped bodies often form secondary clubs, 
even to several generations, which produce cups in the next spring. 
If the clubs are covered with a small quantity of earth, they produce 
much-branched strings of Rhizomorpha, on which new clubs appear 
at all points. In certain circumstances the branches of the paraphyses 
develope into receptacles with conidia ; they often make their appear- 
ance in the cups as forerunners of the ascogenous layer. 

On the sclerotia of these two species of Peziza there often appears 
a pyenidial form which interferes with the formation of the cups. 
Cultivation produced no other form of this fungus, which Brefeld 
calls Pycnis sclerotivora. The germination and formation of the 
mycelium and abstriction of the spores are described in detail. 

With regard to other Ascomycetes, he finds the processes similar 
in all essential points in Peziza cibarioides, Fuckeliana, coccinea, and 
-— aurantia, Otidea leporina, Sarcosphera macrocalyx, Leotia lubrica, Geo- 
glossum, Morchella, and Helvella; except that in the last two genera no 
conidia were observed, and in Peziza Fuckeliana the attempt was 
unsuccessful to obtain from the Botrytis-spores perfect sclerotia which 
developed into cups. All the above-named agree in this point, that 
the differentiation of the hyphe into sterile and fertile takes place 
only when the receptacle has nearly reached maturity. In other 
forms, as Ascobolus denudatus, Erysiphe, Eurotium, Penicillium, 
Melanospora, and Xylaria, this differentiation takes place at a very 
early period. In the first of these, after several generations, large 
masses of thallus arose out of scolecites. In some instances the for- 
mation of conidiophores precedes or accompanies that of the recep- 
tacles; but they may be altogether wanting. Brefeld considers the 
so-called “pollinodia” to have no other function but that of 
enveloping tubes; the conidia and receptacles are therefore of non- 
sexual origin. 

In three small Ascomycetes grown on hare’s dung, one of which 
resembled Ryparobius myriosporus, the formation of the asci could be 


86 SUMMARY OF CURRENT RESEARCHES RELATING TO 


traced back to a single cell or ascogenous filament, as also was 
the case in Melanospora, the perithecial form of Botrytis Bassiana. 

As regards the general structure and position of the Ascomycetes, 
Brefeld regards the three following as the most important points :— 
1. The degradation of the various forms of fructification; 2. The 
disappearance of sexuality, either from the forms of fructification or 
with them; 3. The reversion of sporangia to conidia. All known 
fungi he divides into the two great divisions of Phycomycetes and 
Mycomycetes. To the Phycomycetes belong two classes, viz. :— 
1. Zygomycetes (Mucorinew, Thamnidiew, Choanephoree, Cheto- 
cladiacee, and Piptocephalidee); and 2. Oomycetes (Chytridiaces, 
Saprolegniex, Peronosporee, Entomophthoree, and Ustilagines). 
The Mycomycetes are composed of three classes, viz. :—3. Asco- 
mycetes; 4. Aicidiomycetes; and 5. Basidiomycetes. The lowest 
forms of fungi he regards as nearly related diverging branches from 
a common origin. The same is the case also with the higher forms. 
In both higher and lower forms he finds the same tendency for the 
sporangia to revert to the condition of simple conidia, and for the 
fructification to lose its sexuality. 

The multinucleated condition of the cells of many unicellular 
Thallophytes Brefeld regards as an indication that they are descended 
from multicellular forms from which the cell-walls have disappeared. 
The family in which this degradation has been carried to the greatest 
extent is the Myxomycetes, constituting a third great division of 
the Fungi, in which the cell-walls even of the spores have 
disappeared, the vegetative life being carried on by permanently 
naked cells. , 

Both the higher and lower Fungi may be traced back to a 
sporangiferous parent-form, probably green and belonging to the 
Alge, in which there was already a differentiation into sexual and 
non-sexual forms of fructification. Sexuality was therefore the 
original condition of all Fungi, but has in many cases disappeared, a 
phenomenon not seen elsewhere in the vegetable kingdom. All three 
forms of fructification, or only some, or none, may have degenerated 
to the condition of conidia, Hence we may get forms with only male, 
others with only female organs. The number of forms of fructification 
may also be increased beyond three, as in the Mcidiomycetes. There 
may also be in addition a pure vegetative mode of increase, by the 
breaking up of the mycelium, or the separation of shoots. In these 
cases all other modes of reproduction, all kinds of fructification, 
may disappear, and propagation take place in a vegetative way only. 

The pollinodia of the Ascomycetes not having the male character 
assigned to them by de Bary, Brefeld regards the ascocarp as an 
originally female mode of fructification which has lost its sexual 
character ; the spermatia indicating, in their inability to germinate, 
their original male character. The conidia are the result of degrada- 
tion of the asci. In the Erysiphew, Pyrenomycetes, and Disco- 
mycetes, the apothecia or perithecia may, from analogy, be regarded as 
similar degraded female organs; in the ascophores of Hxoascus and 
Taphrina both sexual and non-sexual forms of fructification occur. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 87 


If the ascus is to be regarded as a sporangium, and the conidia as 
degraded asci, it is clear that no great stress should be laid, from a 
systematic point of view, on the higher differentiation of the fructifi- 
cation, its development into a carpospore, &c. A relationship of the 
Ascomycetes may then be traced downwards with the Phycomycetes, 
upwards with the Aicidiomycetes and Basidiomycetes. In the ascus 
or sporangium is the point of connection with the lower Fungi, in the 
conidia or degraded sporangia that with the higher Fungi; while 
the sporangium further indicates the descent of all the Fungi from 
Algee. 

Influence of Light on the Growth of Penicillium,*—lIn his experi- 
ments on the growth of Fungi in oil,j P. Van Tieghem observed that 
the development of Penicillium glaucum is powerfully affected by 
light. It is only in the spots that are strongly illuminated that 
' the mycelium developes into a continuous coating, very little or none 
appearing on those that remain dark. 

Production of Microphytes within the Egg.t—G. Cattaneo has 
lately occupied himself with the solution of the question whether the 
fungi which so frequently develope within bird’s eggs are introduced 
into the egg from without or whether, as is held by a number of Italian 
investigators to be the case with regard to the Schizomycetes, they 
may arise independently within the egg, out of its own constituent 
elements. A preliminary consideration of the ways by which the 
spores might enter the egg while still in the body—namely, by the 
lungs and air-sacs, by the alimentary canal, and finally by the cloaca 
and oviducts—leads the author to the conclusion that it is most 
unlikely that the spores should enter the developing egg by these 
routes. Thus the development of fungi in eggs shortly after they 
are laid is probably not to be referred to spores introduced from with- 
out, even though the fungi should sometimes enter through the egg- 
shell. His own observations on the development of fungi within and 
upon eggs, which were carried on in a moist chamber, in part upon 
eggs covered with a coat of wax or copal varnish, led to the result that 
the growths of Penicillium, Aspergillus, &c., which often develope in 
such abundance on eggs thus treated, seldom pass into the interior, and 
have not the power of penetrating the skin of the shell; and that, on 
the other hand, the growths of Leptothria and Leptomitus which spring 
up only in eggs which have not become decomposed, are produced on 
the inner side of the skin of the shell, and manifest centrifugal growth 
outwards through the pore-canals of the egg-shell, without showing 
any indication of an entrance from outside. 

Etiology of Diphtheria§—Oertel believes the contagium of 
' diphtheria to be an excessively minute organism, to which he gives the 
name Micrococcus diphtherie. It has an oval form, with a length of 


* Bull. Soc. Bot. France, xxviii. (1881) p. 186. 

+ See ante, p. 81. 

{ Atti Soc. Ital. Sci. Nat., xx. (1 pl.). Cf. Zool. Jahresber. Naples, i. (for 
1879) p. 123. 

§ ‘Zur Aetiologie der Infectionskrankheiten’ (1881) pp. 199-246. See Bot. 
Centralbl., vii. (1881) p. 269. 


88 SUMMARY OF CURRENT RESEARCHES RELATING TO 


1-1'5 p, and a breadth of 0:3 w; larger individuals, found nearer 
the surface, being 4°2 » longand 1:1, broad. Where the individuals 
are more scattered, they occur mostly in pairs, rarely a number con- 
nected into a torula-like chain. When present in masses the cells le 
so close together that it is difficult to determine whether they 
are connected or not. They are then imbedded in a gelatinous 
envelope, and thus combined in masses into a colony. Addition of 
acetic acid makes the mass clearer, so that the combination in pairs 
and the more rod-like form of the separate cells is more readily seen. 
These organisms penetrate the epithelium. They are found chiefly 
in the mouth and throat; and may be conveyed through the air, 
by direct contact, through the saliva, or by contact with a great 
variety of objects, as plates or drinking glasses, clothes, toys, linen, 
&e. The most favourable nidus for their development and fatal 
activity is when, from injury to the cuticle, they come into direct 
contact with the blood and tissues. 

The author believes the micrococcus to be specifically distinct 
from those which produce other infectious diseases. The apparent 
spontaneous production in some cases of diphtherial disease may arise 
from the germs being present in some other organism in a different 
form, in which it is incapable of producing disease, or from its being 
present in the infected subject in a latent condition, waiting favourable 
conditions for its development. The average length of time through 
which the disease runs before reaching its culmination may be stated 
as from two to five days. 

Properties and Functions of Bacteria.*—Prof. J. B. Schnetzler 
finds that Bacteria, as well as Infusoria of the genus Vorticella, live 
and exhibit activity in a solution of curare; moreover the muscles 
and cilia of the Turbellarian Planaria torva and some of the muscles 
of Gammarus pulex were found to act with energy after being exposed 
to the same reagent for twenty-four hours. But Bacillus subtilis is killed 
immediately by perchloride of iron solution. The bacteria produced 
during decomposition of a plant do not produce fatal results when 
injected into the vessels of a rabbit. Prof. Schnetzler shows that a 
highly organized plant may be watered exclusively by a fetid liquid 
full of bacteria, without undergoing fermentation or decomposition 
of its parts; the bacteria (Micrococcus and Bacillus) may be found 
in the leaves, but they also occur in those of plants which have been 
watered with ordinary water. - 

Finding bacteria in the condensed moisture which appears on the 
cover of a vessel containing bacteria and green algz, Prof. Schnetzler 
explains their appearance there by the bursting of the bubbles of 
oxygen which rise to the surface under the influence of sunlight and 
in bursting scatter the bacteria which they have brought up with 
them. 

Atmospheric Bacteria.t—Continuing his previous investigations, 
on this subject,; P. Miquel gives the averages since obtained by him, 


* Bull. Soc. Vaudoise Sci. Nat., xvii. (1881) pp. 625-32. 
+ Bull. Soc. Bot. France, xxviii. (1881); Rev Bibl. p. 11. 
t See this Journal, iii. (1880) p. 837. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 89 


showing for each month the quantity of spores in the air of Mont- 
souris, and describes some interesting facts concerning the cultivation 
of bacteria. 

Bacillus wrece, cultivated in neutral bouillon, fails to the bottom 
of the vessel, and dies, leaving the liquid perfectly transparent; but 
if a little pure urea is added when the parasite is living, the fluid 
becomes cloudy and charged with carbonate of ammonia. Of all the 
species cultivated by the author in a state of purity, none abandoned 
their special aptitudes nor departed from the cycle of evolution 
proper to each. Certain illusions and analogies are therefore to be 
guarded against. Bacilli, in the absence of oxygen, can assume a 
resemblance to Bacteria, and Bacteria when dead are easily confounded 
with Micrococet. 


Pathogenous Bacillus in Drinking Water.*—J. Brautlecht has 
detected in drinking water, which was considered to be the partial 
cause of an epidemic of typhus, a bacillus which he cultivated in a 
solution of 3 per mil. gelatine in spring water, with 25 per cent. 
ammonium phosphate. This was distinguished from other non- 
pathogenous bacilli by the absence of any powerful reducing action 
and also of the offensive odour of some other species; having a 
pleasant odour somewhat like that of boiled milk. This bacillus 
forms filaments in the nutrient fluid, which soon break up into short 
rods, which separate into cocci loosely connected in a moniliform 
manner. In later cultures only rods and cocci were visible, which 
did not exhibit any spontaneous motion. Besides the suspected 
drinking water, a bacillus with the same characteristics was found in 
the urine of typhus patients, also on the surface of thick masses 
of putrefying alge. When inserted beneath the skin of a rabbit, 
these bacilli caused violent fever in from 18 to 36 hours. 


Connection of Diseases with specific Bacilliij—H. Buchner 
describes a series of experiments for the purpose of determining 
whether contagious diseases are caused entirely by the bacilli which 
are found to accompany them, or whether the action of these is 
assisted by a peculiar chemical substance resulting from the diseased 
tissue. The results pointed entirely in the direction of the first of 
these hypotheses. It was found in the first place that the cattle 
disease was produced by bacilli originally taken from diseased 
subjects, even when these had been cultivated to thirty-six genera- 
tions, when it was impossible for the least trace of any disease-producing 
substance to exist which had come directly from the diseased subject. 
In the second place, it was found, after repeated and long-continued 
culture, that these disease-producing bacilli differed in no visible 
respect from the bacilli produced spontaneously in hay; while with 
the latter he was able to produce the disease by injecting it into the 
blood of white mice and rabbits. 


* Virchow’s Arch. path. Anat., Ixxxiv. p.80. See Naturforscher, xiy. (1881) 
p- 320. 

+ ‘Zur Aetiologie der Infectionskrankheiten,’ 1881, pp. 69-94. See Bot. 
Centralbl., vii. (1881) p. 237. 


90 SUMMARY OF OCURRENT RESEARCHES RELATING TO 


Origin of the lowest Organisms.*—F. Krasan, in an extraor- 
dinary production published in the Transactions of a learned Society 
as a serious paper, discusses the hypothesis of a possible archibiosis 
in the case of the lowest organisms, and supports his opinion in 
favour of this mode of origin in at any rate a spirited manner by the 
results of a series of experiments. He does not contest the argu- 
ment that many of the lowest forms arise from such germs as may 
be contained in dust, but insists that the proof of such an origin 
is much hindered by the mechanical difficulties of manipulation. 
The experiments are divided into three series :— 

1. Relations of Bacteria to certain microscopic structures con- 
tained in the seeds of many plants, and the action of phosphate of 
hydrogen, soda, and ammonia (microcosmic salt) and atmospheric 
dust :— 

The close connection alleged to exist between bacterian move- 
ments and the molecular movements of organic particles is illus- 
trated by the phenomena exhibited by drops of oil derived from 
seeds, such as those of the parsnep and of melons and gourds, also 
hazel-nut kernels, broken up in water (either distilled, stream, or 
spring water). These drops are of different sizes, and generally 
contain vacuoles filled with water, coloured pale red, and each sur- 
rounded by a bluish-green halo, the whole mass being greenish-grey 
or pale green; they consist of a mixture of oil, albumen, and a 
carbohydrate. If one of the superficial vacuoles is closely examined, 
it is seen to contain an immense number of very minute roundish 
bodies in rapid movement of a swarming character. The vacuole 
increases in size by pushing its way to the exterior, where it finally 
bursts, discharging its contents into the surrounding water; a small 
portion remains, and is enclosed by the collapsed oil-globule. The 
minute bodies thus liberated move towards the edge of the cover- 
glass, and at the same time approach each other in pairs, and after 
rotating very rapidly become quiescent and unite, forming cylin- 
drical masses. These are considered by the writer to be half-formed 
bacteria, and they are said to be almost identical in appearance with 
true bacteria, but differ in possessing the property of dichroism, 
which becomes more marked towards the edge of the glass, and is 
probably, together with the phenomena of conjunction, connected 
with the proximity of the air. These bodies may be dried, and yet 
resume their characters when again moistened. 

The following differential experiments were undertaken. To 
equal parts of a 55 to 6 per cent. solution of sugar in distilled water 
was added a rather smaller proportion of gypsum or freshly 
burned coal-ash (rich in sulphate of lime); to one-half of the 
mixture was added 20-40 milligrams of atmospheric dust, to the other 
half 4-8 milligrams of the phosphate salt; both were stirred, covered, 
and set aside in a temperature of 10°-14° C. In 48 hours the dust- 
containing mixture contained isolated bacteria in active movement, 
while the other showed quantities of them, forming groups on the air- 
bubbles; thus a small amount of the phosphate salt was more pro- 


* Verh, zool.-bot. Ges, Wien, xxx. (1881) pp. 267-327 (1 pl.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 91 


ductive of bacteria than five times its proportion of atmospheric dust ; 
in the latter case the forms are chiefly Bacterium lineola, in the 
former B. termo; this difference bespeaks a different origin for the 
two growths. 

Solution of sugar and the microcosmie salt and coal-ashes in dis- 
tilled water produced no bacteria in 28 hours after addition of dust, 
and but few when left to itself, but with a drop of bacterian liquid it 
contained abundance, arranged in tracts; in 455 hours the condition 
was essentially the same, but after 68 hours the dust preparation 
contained an abundance in masses; also the uninfected solution, but 
here development appears to have begun four or five hours later than 
in the dust preparation. 

Pieces of an almond more than two years old were boiled fora 
minute in distilled water, and the decoction put while hot into 9 watch- 
glasses, “cleaned, as usual, as well as possible,” and covered up. The 
contents of these glasses were variously treated, with the following 
results :— 

No.1. Left untouched ; developed a yeast-fungus and: some mycelia, 
after the lapse of 22 days. 

No. 2. Similarly treated; was filled with mould and fermentation 
fungi after 13 days. 

Nos. 3, 4, and 5, having received, the one 2 grams, the other a 
drop of distilled water, the third a drop of emulsion of almond kernel 
in distilled water, were clouded with a minute bacterium in 48 hours. 

No. 6 received two pieces of almond, and began to be clouded 
with a bacillus in 70 hours. 

No. 7, infected from an emulsion full of bacteria, swarmed with 
the same form in 24 hours. 

No. 8, which had received a few milligrams of atmospheric dust, 
showed some larger bacteria, some being united into rods and chains, 
after 44 hours. 

No. 9 was infected with a dried-up drop of bacterium liquid, and 
became cloudy in 40 hours. 

From these and similar experiments Krasan concludes, first, 
that heat disorganizes the molecules of organic substances so as to 
render them incapable of becoming rearranged into organic structures 
without the stimulus of fresh air or other agents; secondly, this 
stimulus need not proceed directly from organic germs strictly so 
called, but may just as well be derived from the fresh air itself. 
Water and various liquid and solid organic substances are employed, 
which are either unaltered by heat, or else have been long in contact 
with fresh air. 

Krasan considers the possible inorganic origin of low organisms 
absolutely proved by his finding them developed first in the Micro- 
coccus-, then the Zooglea-form in a precipitate of calcium phos- 
phate in calcium sulphate solution to which sugar had been added; 
he has observed them to arise from minute granules which occur in 
the freshly formed precipitate, and considers it due to decomposition 
of the sugar molecules and recombination of their radicals with the 
other constituents. 


92 SUMMARY OF CURRENT RESEARCHES RELATING TO 


2. Development of Monads.—Under this term are here included 
only low organisms of the form of swarm-spores, about 4 micro- 
millimetres in diameter. These become very slow in their move- 
ments, and proceed to reproduce by fission in very concentrated 
emulsions, but when transplanted to a dilute liquid become very 
active, and exhibit the peculiarity of attracting particles of various 
sizes and expelling them again with vigour, a process set down to an 
electric energy, residing in its greatest power at the base of the 
flagellum. Investigations extending over two years failed in dis- 
covering another mode of increase but that by fission. Repeated experi- 
ments, however, of which the object—viz. that of discovering a 
method of genesis which dispenses with any antecedent organism 
is not concealed, were, so the author relates, at length rewarded. 
Some “ aleuron-granules” from hazel-nut kernels mashed-up in 
water, were observed to resolve themselves into granular jelly-masses 
of globular form; from this mass the monad is said to de- 
velope, or several may arise from a single mass. A large monad with 
a proboscis was seen to arise from an aleuron-granule by fission of its 
substance and extension of the gelatinous material at two opposite 
points, forming a fusiform body ; if the formative mass is larger than 
the normal monad it divides and forms two. Oily drops of pro- 
toplasm also become converted into monads. The production of 
these organisms is dependent on the time during which the seed has 
been left to dry in its shell. Monads were also produced from a 
mixture of sugar and stream or spring water and a phosphate, by con- 
traction or fission of the flocculent precipitate contained in it. ‘T'wo 
sizes of monads are produced from a solution of Umbelliferous seeds 
in spring water; the larger are derived from the smaller. Ciliated 
Infusoria are said to have been seen to develope from zooglcea- 
masses; the process occurs in the early morning, between | and 4 a.m. (!) 
Leucophrys is generated with especial ease from water, sugar, and a 
phosphate. Thundery evenings in August and September are the 
best times for such developments to occur; monads and ciliated 
Infusoria are mutually exclusive, and do not develop from the same 
solution. 

3. Effects of Contact are the subject of the third and last series of 
investigations. Krasan finds that the development of bacillus in 
infusions of seeds in boiling water is almost entirely dependent on 
the retention in the fluid of the solid bodies used to make the 
infusion ; but that the presence of ali kinds of solid bodies in infusions 
of other kinds considerably facilitates and is indispensable to their 
development; the result of this is thus stated. (1) Solid particles 
and heterogeneous bodies in a solution of formative organic sub- 
stances exercise a favourable influence on the process of formation by 
their presence, and being in contact with the solution, inasmuch as 
they accelerate the interchange of matter, and give a definite direction 
to the organizing activity of the molecular forces. (2) The nature 
of the foreign bodies is not without influence on the size, form, con- 
sistence, colour, and mobility of the organisms which are produced. 

The author invokes the action of physico-chemical forces in 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 93 


aid of his theory, and explains the phenomena on which he based it; 
chiefly appealing to the different electrical polarities of the substances 
employed—a line of argument familiar to most of those who have 
studied the question of the origin of life. 

It is to be observed, in estimating the scientific value of these 
experiments, that the highest magnifying power mentioned as being 
employed is 610 diameters, and that as a rule no special attention 
appears to be given to the cleaning of the vessels, or the sterilizing 
of the air or water, the latter being as often ordinary spring- or 
stream-water as distilled. The value of the reasoning is still further 
impaired by the fact that the latest experiments which have been 
adduced in opposition to the ancient theory here advocated afresh are 
dismissed without much consideration, even those of Tyndall receiving 
but scanty attention. 


Prolongation of Vegetative Activity of Chlorophyllian Cells 
under the influence of a parasite.*—According to the Schwendenerian 
theory lichens are complex organisms, consisting of an alga, and a 
fungus which is parasitic on it. It seems extraordinary that the alga, 
thus embraced by a parasite, not only continues to live, but increases 
and multiplies, and is apparently endowed with new vigour. The 
same alga, alone, becomes discoloured and disappears on the return of 
the dry season ; but in the lichen state it often persists for years. - It 
has been said by Rees, that there are no other such cases known of 
vegetative activity being prolonged under the influence of a parasite ; 
but Max Cornu has lately called attention to several. Thus, maples 
are often attacked, late in summer, by an Hrysiphus which occupies 
the under surface of the leaves. The parts thus occupied remain 
green when the rest of the leaf has withered, and even after the leaf 
has fallen. Similarly with a parasite which attacks leaves and fruits 
of pears, apples, &c. ; indeed, the fact is very general ; the chlorophyll- 
cells attacked retain their green and their vital activity longer than 
the others. The phenomenon is explained by the fungus counter- 
balancing the return of nutritive matters towards the reserve centres. 
Green alge have a vegetative period, during which they retain this 
colour very intensely; then they grow yellow and form durable 
Spores, after which the vegetative part dies. In lichens the fungus 
prevents this development of spores, and so favours the life of the 
alga. Flowering annuals similarly may be preserved many years by 
prevention of flowering. 


Algee. 


Classification of Nostoc.—In the second fasciculus of MM. 
Bornet and Thuret’s ‘ Notes algologiques,’ M. Bornet gives a full life- 
history of the genus Nostoc, including the germination of the spores 
and the development of the hormogonia, which display motility after 
their escape. The thickening of the filaments takes place in many 
Species, without having any specific value. With Nostoc M. Bornet 


* Comptes Rendus, xciii. (1881). See also Mr, P. Geddes’ recent researches 
on “ Animal Lichens,” ‘ Nature,’ xxv. (1882) pp. 303-5. 


94 SUMMARY OF CURRENT RESEARCHES RELATING TO 


unites Monormia Berk. and Hormosiphon Kg., and distinguishes the 
following groups and species. 

1. Intricata. Aquatic, softly gelatinous, without definite form, 
often floating :—N. Hederule Men., tenuissimum Rbh., Linkia Roth., 
intricatum Men., crispulum Rbh., piscinale Kg., carneum Ag., rivulare 


Kg. 


2. Gelatinosa. Fixed; soft and gelatinous. Cells of the young 


filament elongated cylindrical. Spores large, elongated :—WN. spongie- 
forme Ag., gelatinosum Shousboe, ellipsosporum Rbh. 

8. Humifusa. Terrestrial. At first globular, afterwards coalescent 
and gelatinous, forming coatings adherent to the substratum. Spores 
smooth :—N. collinum Kg., muscorum Ag. var. tenax Thur., Passerint- 
anum De Not., humifusum Carm., calcicola Bréb., foliaceum Morg. 

4. Communia. ‘Terrestrial, occasionally aquatic. At first globu- 
lar, subsequently tongue-shaped, flat and irregular, not attached to 
the substratum :—N. cimiflorum Tourn. (commune Vauch.). 

5. Spherica. Globular, or often irregularly round when they 
grow larger. Surface firm and resistent:—N. sphcericum Vauch., 
rupestre Kg., macrosporum Men., sphaeroides Kg., ceruleum Lyngb., 
minutissimum Kg., gregarium Thur., edule Mont., and Berk., pruni- 
forme Ag. 

6. Verrucosa, Aquatic; rounded or disk-shaped, at first solid, then 
hollow, protected by a firm tough membrane. Filaments delicate, 
distant, and somewhat curved in the middle, crowded and much bent 
at the ends:—N. verrucosum Vauch. » par melioides Kg. 

7. Zetterstedtiana. Aquatic ; ‘globular, Hangs warty, divides 
readily into separable segments :—WN. Zetterstedtianum Aresch. 

8. Flagelliformia. Terrestrial; narrow, linear, forming dichoto- 

gmously divided bands :—WN. flagelliforme Berk. 


Diatoms of Thames Mud.*—Dr. F. Bossey has investigated the 
fresh- and salt-water diatoms found in mud-banks in the Thames, for 
the purpose of showing the influence of the flood and ebb tides on their 
formation, and gives the details of the result in an elaborate table. 

Mud taken from seven different localities showed the following 
proportions of fresh-water and salt forms :— 


Fresh water. Salt. 
Half a mile above Teddington Lock 66 0 
One mile below Teddington Li Lock . 54 0 
Kew . oe ; 52 37 
Blackwall sig hake Hear 39 45 
Estuary of the Thames .. .. .. 9 60 


Dr. Bossey considers that in face of these facts the study of the 
natural history of the Thames mud affords important evidence in 
support of the position taken up by the Conservators of the Thames, 


that the mud-banks forming in the river owe their origin to the. 


discharge of matters from the outlets of the main-drainage system, 
* Proc. Holmesdale Nat. Hist. Club, 2 pp. and a table. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 95 


MICROSCOPY. 


a. Instruments, Accessories, &c.* 


Goltzsch’s Binocular Microscope.t—We give the description of 
this Microscope, translated from the author’s German original, with 
slight modifications only. 

“This Microscope (Fig. 8), which is simple to the highest 
imaginable degree, is calculated to obviate a number of theoretical 
and practical objections 
which may be raised 
against instruments of 
the same kind hitherto 
described. In particular 
- we get rid of — 

(1) All difficulty in 
combining the images 
and all strain to the 
eyes. 

(2) All variation in 
magnitude and distinct- 
ness, as also in the ad- 
justment of the images. 

(8) All difficulty in 
accommodating the in- 
strument for different 
widths between the 
eyes. 

(4) The influence 
which the thickness of 
the glass prisms, ana- 
logous to the known 
influence of the thick- ! 
ne f the rin = GTI 
Be cise ccs co = 
the course of the rays. 

And lastly, instead of the double reflection, which is not avoided 
in any of the instruments known, there is only a single reflection for 
each half of the rays.} 

All these advantages are obtained by a slight modification in the 
manner in which the images are produced. Whilst in the case of the 
compound Microscope the object must always be a little beyond the ~ 
focal point, and in the simple Microscope is generally nearer, in 
the new arrangement it is brought to the focus itself, so that the 
pencils of rays proceeding from the different points of the object, 


UO 


WE a= 
) 


AUNT 
jun 


* In this section are also included optical notes, notices of books relating to 
the Microscope, and miscellaneous microscopical notes. , 

+ Carl’s Repert. f. Exper.-Physik, 1879, pp. 653-6 (1 fig.). Zeitschr. f. 
Mikr,, ii. (1879) p. 166-9. 

t The author appears not to have seen the Stephenson binocular. 


96 SUMMARY OF CURRENT RESEARCHES RELATING TO 


although their inclination to the axis is different, leave the objective 
as pencils of parallel rays, and therefore of themselves produce no 
image, or rather one at an infinite distance. The convergence of the 
pencils of rays requisite to produce a real image is effected after- 
wards by means of the eye-pieces, which consequently it would be 
more correct to regard as telescopes, though they consist, like ordinary 
microscopical eye-pieces, only of two plano-convex lenses of crown 
glass, the ratio between their focal lengths being about 1:3. It will 
be seen at once that, by employing this telescopic eye-piece to receive 
the pencils of rays emerging parallel from the objective and coming 
as it were from an infinite distance, it is not necessary that Micro- 
scopes thus constructed should be of a fixed length. The length may 
be altered at will without producing any change in the amplification 
and distinctness of the image after it has been once obtained, provided 
the telescopic eye-piece is so adjusted, by means of a draw-tube 
arrangement, that distant objects can be clearly seen by it. It is 
equally obvious how, by this process, the exact parallelism of the 
pencils of rays emerging from the objective, and consequently the 
position of the object in the focus, is regulated and known. This 
furnishes us with a basis which renders it possible to obtain such a 
direction for each half of the pencil of rays by a single reflection that 
each eye can take in one of the halves. 
In the original axis of the Microscope there are placed two glass 
prisms, a smaller, A, Fig. 4, and a larger one B, which are fixed in 
such a manner that the smaller prism 
Fic. 4, causes one half of the rays and the larger 
prism the other half to be diverted from 
the axis under different angles by total 
reflection. The two pencils D E of 
parallel rays, are directed into the eye- 
pieces through two tubes which converge 
slightly towards the lower extremity. 
The original axis of the Microscope hes 
horizontally, and on the right of the 
observer is the objective C, the stage, 
and the illuminating apparatus; the 
observer looks down from above (in a 
E D direction inclined as may be desired) 
through the two converging tubes, 
directly upon the horizontal axis and 
with each eye over one of the two reflect- 
ing prisms. The first of these of course 
projects only as far as the axis, so as to 
leave half the opening free for the second. 
They are so arranged on the axis that 
they, with the eye-pieces to which they 
are attached, can be moved by rack and 
pinion so that their distance apart corresponds with the distance 
between the eyes of the observer, without the image being affected 
by the difference or alteration in the course traversed by the pencils 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 97 


up to the first lens of the eye-piece, their rays being parallel. To 
this parallelism it is due likewise that every disturbing effect (like 
that which the thickness of the cover-glass exerts) by the prisms on 
the transmitted pencil is excluded, for such effects can only be pro- 
duced by converging or diverging pencils. 

The mode of using an instrument so constructed does not differ 
from that of an ordinary Microscope, except that first the two eye- 
pieces must be removed and adjusted for infinite distance, and then 
replaced. By means of the adjusting movement the left eye-piece 
tube is then put in such a position that with proper illumination the 
two diaphragm apertures of equal size, which are inside the eye- 
pieces, are seen without effort as one ; an object being now introduced 
and brought into focus, the plastic image infallibly appears, and 
cannot be seen double. To produce this effect in perfection, however, 

-the position of the prisms must be so adjusted that the images 
together with the diaphragm apertures become merged into one com- 
plete whole, and the impression is produced of looking through a 
round opening at the object which is behind. After this position of 
the prisms has been once fixed no focussing that may be necessary 
alters the effect. The figure shows that the half of the rays which 
pass to the second prism is that furthest from the observer; in the 
opposite case the effect would be pseudoscopic. 

Plane mirrors of glass may be used instead of the prisms, but 
the surfaces of both the prisms and the mirrors must of course be 
perfect. The prism which is inserted half-way, A, is best made 
equilateral, because with a rectangular one the total reflection might be 
questionable, and the edge is better; the other may be rectangular, 
and should be of such a size that when the first is re- 
moved it can take in and reflect the full pencil of rays; 
we then have a monocular Microscope. It is obvious that 
instead of the eye-pieces described, actual achromatic 
telescopes could be used.” 


Hartnack’s Demonstration Microscope.* — This 
(Fig. 5) consists of a tube, carrying eye-piece and objective, 
fixed to a frame by which it can be held in the hand. A 
micrometer screw a serves for focussing the object which 
is fixed to the circular stage by clamps. The continua- 
tion of the stage forms a metallic drum, at the lower end 
of which is a convex lens L to concentrate light on the 
object. A diaphragm-disk is inserted in the drum with 
a portion of its margin projecting on one side so as to be 
revolved by the finger. 


Lacaze-Duthiers’ Microscope with Rotating Foot—M. Nachet 
has supplied us with a drawing (Fig. 6) of a Microscope similar to 
that which we described at p. 873 of Vol. III. It is the device of 
Professor H. de Lacaze-Duthiers. 

The speciality of the instrument is that the bottom of the pillar 


* Thanhoffer’s ‘Das Mikroskop und seine Anwendung,’ 1880, p. 55 
(i fig.). 
Ser. 2.—Vot. II. H 


98 SUMMARY OF CURRENT RESEARCHES RELATING TO 


is attached to a movable ring so that the rotation is on the base and 
not on the stage (as in the larger Nachet models), the mirror remaining 
fixed. 


Fig. 6. 


The special object of the design is stated to have been to reduce 
the height of the instrument as much as possible, the method adopted 
for the rotation “allowing the stage to be less elevated above the 
table and thinner.” 


Nachet’s Portable Microscope. — This Microscope is shown in 
Figs. 7 and 8 set up for use as a table Microscope. Fig. 8 is intended 
to show its application to the observation and dissection of large 
surfaces or objects contained in small troughs or tubs. By loosening 
the milled ring just above the stage (A, Fig. 8, C, Fig. 9) the com- 
pound body can be removed, and an arm L carrying a lens or 
doublet substituted. To put the instrument in its box (Fig. 11), the 
stage P (Fig. 10) is turned completely over on the pivot O, and the 
base is then only 4°5 cm. in height. The box is 19 cm. x 11 cm. x 
6 cm. 

The instrument seems to be an excellent solution of the problem 
of constructing a Microscope which shall be really “portable” and 
at the same time quite steady for ordinary use. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 99 


Mic 3 


ab || a 


ee 


| 


100 SUMMARY OF CURRENT RESEARCHES RELATING TO 

Parkes’s “ Drawing-room”’ Microscope.—The peculiarity of 
this Microscope (apart from its title and golden colour) consists in 
the revival of the “magnetic bar adjustment” to the stage, a device 
originated by Mr. G. Busk. 

Piffard’s Skin Microscope.—Dr. Stowell recalls * the Microscope 
for the examination of the skin, devised by Dr. H. G. Piffard,t to 
obviate the inconveniences attendant upon a simple lens of high 
power, which “often involves a constrained position of the head and 
neck, and in some cases an unpleasant proximity to the subject under 


investigation.” 
Dr. Piffard’s description is as follows :—* A (Fig. 12) represents 
the body of a binocular Microscope made by Nachet, from which the 


Fig. 13. 


ic EA 
HT 


Fie. 12. 


a | 


=. SS = 


reflecting prism situated above the objective was removed, and another 


of the same focus but double the size substituted. B is a double nose- 
C is the pinion for 


piece carrying two objectives of different powers. 


fine adjustment (raising and lowering the horizontal arm) ; and D the 
clamping screw for coarse adjustment, the whole apparatus sliding up 
and down the rod. E is a rod, five feet in length, which supports the 


other apparatus, and is itself supported by a cast-iron foot not shown in 


* ‘The Microscope,’ i. (1881) pp. 33-8. (1 fig.). 
‘An Elementary Treatise on Diseases of the Skin, for the use of Students 


t 
and Practitioners, (8vo, London and New York, 1876.) See pp. 32-41. (1 fig.) 


—_— -—_——. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 101 


the drawing. Other adjustments permit the body of the Microscope to 
be placed in a horizontal or any other desired position. . . . With the 
instrument described, any portion of the integument, from the scalp 
to the sole of the feet, can be conveniently examined, and a prolonged 
examination can be made without fatigue to the observer.. It is an 
instrument which I cannot too highly recommend to those desiring a 
thorough knowledge of the surface aspect of the skin and its lesions.” 


Robin’s Dissecting Microscope.—This (made by MM. Nachet) is 
shown in Fig. 13, with their erecting eye-piece. The stage is arranged 
so as to provide rests for the hands on either side of the dissecting 
plate. : 


Briicke Lens.—A description of this lens (Fig. 14), much in use 
on the Continent, does not appear in any of the English books on the 
- Microscope. We take the following from M. Robin’s treatise.* 

“To remedy the inconvenience of the lens being too close to the 
object in all but low powers, Charles Chevalier in his ‘Manuel du 


Fia. 15, 


Micrographe’ (1839) proposed ‘to place above a doublet a concave 
achromatic lens, the distance of which could be varied at pleasure. 
The effect of this combination is to increase the magnifying power 
and lengthen the focus. Thus arranged, this instrument will be the 
most powerful of all simple Microscopes, and the space available for 
scalpels, needles, &c., will be much greater than with a doublet alone. 
The further the concave lens is removed from the latter, the greater 
will be the amplification.’ This combination, applied to lenses for 
examining the eye and skin, allows the use of doublets which leave 


* Robin, C., ‘ Traité du Microscope et des Injections,’ 2nd ed. (8vo, Paris, 
1877), pp. 33-4 (1 fig.). 


102 SUMMARY OF CURRENT RESEARCHES RELATING TO 


a considerable distance above the object, and it is this idea which 
has governed the construction of the Briicke lens. 

“The lens has a very long focus, and the construction is that of 
the Galileo telescope as applied to opera-glasses, but the amplification 
of the objective is much greater than that usually obtained in opera- 
glasses. ‘The focus is about 6 cm., and the power three to eight times. 
The latter power is obtained by lengthening the tube, by which means 
the distance between the two lenses is much enlarged and the amplifi- 
cation increased without inconveniently modifying the focus. 

“This lens may be used in place of the body of a compound 
Microscope when it is desired to dissect or to find small objects, or it 
can be adapted to a simple Microscope or lens-holder with from 3 to 
8 cm. between the object and objective.” 

Kiinckel d’Herculais devised .a holder for the lens shown in 
Fig. 15. By tightening the screw on the horizontal arm the “jaws” 
are separated or closed. The arm can be lengthened if desired and 
also raised or lowered by the rack and pinion. L is the place for the 
lens and O for doublets. 


The Model Stand.*—Mr. J. D. Cox discusses the changes that 
have taken place in microscope-stands with a view of determining 
which will be of permanent value and should form part of the features 
of a complete stand, and thus summarizes the essential requisites 
which ought to be embodied in every instrument intended for real 
scientific use. 

1. A firm and rigid arm having the general character of the 
Jackson model, carrying the body of the instrument, with coarse and 
fine adjustments conveniently placed below the body, with perfectly 
even and reliable motion. 

2. A firm ring as the basis of the stage, to which any form of 
stage-plate, plain with clips, glass, or mechanical, may be adapted and 
interchanged. Nearly every microscopist has work to do for which a 
mechanical stage is almost indispensable, such as micrometric measure- 
ments, and the systematic sweeping of a slide to make sure that every 
part has been examined. There should be no rack and pinion move- 
ment for revolving the stage as it can be better done with the fingers, 
nor a centering adjustment unless the instrument is intended for 
goniometry. The stage thin enough to allow the use of light of at 
least 70° obliquity from the axis of the instrument. 

In regard to the requisite of reversibility for the stage, Mr. Cox 
points out that in nearly every department of natural science (and not 
for diatoms only) there is need of the occasional use of light of 


extreme obliquity upon dry mounts and from the mirror alone, so. 


that an easily reversible stage is desirable. If, however, immersion 
illuminators came to be used for dry mounts as well as those in 
balsam + a reversible stage would not be necessary, as a ray incident 
at 41° only would emerge at the maximum obliquity of 90°. 
3. A grooved bar—immovable and not swinging—for the support 
* Amer. Jour. Micr., vi. (1881) pp. 89-95 (4 figs.). 


+ This should read “ for dry objectives as well as immersion.” Balsam mounts 
are on the same footing as dry mounts when a dry objective is used, 


by by 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 103 


of the substage with centering screws and which may or may not be 
fitted with rack and pinion movement. No illuminating apparatus to 
be attached to the bottom of the stage proper. The diaphragm with 
tapering nose so that it can be racked up close to the bottom of the 
slide. 

4. The mirror-bar to swing on the optical centre of the instru- 
ment above as well as below the stage, and to have a sliding extension 
so as to increase the distance between the mirror and the stage without 
changing the angle of the incident light. 

5. Such form of base as will permit the mirror to be swung 
laterally when the instrument is in upright position. 

Mr. Cox objects to the substage and mirror-bar swinging together, 
on the ground that it is then necessary to attach “the immersion 
illuminators to the bottom of the stage by some special means, such 
as bayonet catch, screw in the stage-well, &c.,” and he advises that all 
such apparatus should be used in the substage for which it was in 
fact devised. He suggests and figures an attachment to carry an 
immersion illuminator, consisting of a movable elbow-piece on a 
slotted arm sliding on a pin that screws on the outer end of a short 
right-angled dove-tail slide fitting into a corresponding bar cast on 
the substage carrier that racks or slides on the fixed tail-piece. This 
appears to us, however, a complicated way of applying a simple im- 
mersion illuminator such as the hemispherical lens, and we cannot 
see any objection to mounting the lens in a disk to fit into the stage- 
well or the under surface of the rotating stage plate. 

For use with the Continental stands that are not provided with 
mechanical stages, Mr. Zeiss mounts the lens in a disk of brass which 
drops into the bevelled central stage opening, the plane face is then 
flush with the surface of the stage. 


Denomination of Eye-pieces and Standard Gauges for same.— 
The Committee appointed by the Council in October last to consider 
the question of standard gauges for eye-pieces (and substages) duly 
presented their report, which was thereupon ordered to be printed 
and circulated amongst the members of the Council, and is now 
under consideration. 

Subsequently to the report being made, the following circular 
was received by some of the English opticians from a committee of 
the American Society of Microscopists, unfortunately too late to be 
laid before the Committee. 

“1st Question.—Please give list of various eye-pieces or oculars for 
the Microscope made by you, with construction (Huyghenian, ortho- 
scopic, periscopic, &c., &ec.), with the equivalent amplifying power of 
each, at a standard distance of 10 English inches or 254 mm. 

2. Please state how you determine the amplifying power of your 
eye-pieces. 

3. Do you consider it desirable that a uniform nomenclature 
(with reference to amplifying power) of eye-pieces should be adopted 
by makers of Microscopes ? 

4, Will you adopt such a nomenclature if decided upon by this 
Society ? 


104 SUMMARY OF CURRENT RESEARCHES RELATING TO 


5. Please suggest such a nomenclature which seems to you most 
generally applicable and desirable. 

6. Do you consider it desirable that eye-pieces should be so con- 
structed—by means of a shoulder or other device on the longer ones— 
that all should pass the same distance into the tube of the Microscope, 
thereby preserving the blackening of the inside of the microscope- 
tube ? 

7. Please give inside diameter of microscope-tube, or draw-tube 
where there is one, or outside diameter of that portion of eye-piece 
fitting into the microscope-tube for each size of stand made by you. 

8. Do you consider it desirable that two, or three, or more standard 
diameters of tube for Microscopes be generally adopted with a view to 
interchangeability of eye-pieces ? 

9. Please suggest the number of sizes and the inside diameter of 
tube in each case, which you would recommend for adoption. 

10. Will you adopt a standard set of sizes if agreed upon and 
recommended by this Society ? 

11. Please give this committee the benefit of any suggestions not 
included in the above answers.” 

The inquiry of the American committee embraces a wider field 
than that of the Society’s committee, which was limited to the ques- 
tion of standard gauges for eye-pieces and substages, and does not 
include a consideration of the proper denomination for eye-pieces, 
though the present system of nomenclature is an even greater evil 
than that of the numerous different sizes. 

Every one feels the inconvenience of the Continental method of 
numbering or lettering objectives, a special table being necessary to 
enable the relative powers of Monsieur A’s No. 2, and Herr B’s 
No. 3 to be compared; the English plan of denoting the objective 
by inches and fractions of an inch is obviously preferable. 

Having adopted this improvement, however, and even being accus- 
tomed to wonder how our Continental brethren can still tolerate so 
barbarous a system of marking objectives, it is remarkable that 
the designation of eye-pieces should have been allowed to remain 
on the principle abandoned for objectives, and that the letters A, B, 
C, D, &c., by which they are known, should still express absolutely 
nothing as to their magnifying power, beyond the fact that I) is to 
some undefined extent more powerful than C,C than B, and Bthan A; 
so that not only is it impossible to compare the eye-pieces of dif- 
ferent makers, but it is not possible to do so in the case of the same 
maker, unless the powers are actually known. 

If eye-pieces were, however, denoted on the same principle as 
objecs yr nothing whatever would be lost, and much would be 
gained. 

For instance, if the magnifying power of a }-inch objective with 
a C eye-piece is required, it will be 500 or 750, according as the eye- 
piece is that of one or the other maker. If, however, instead of 
being labelled C (or No. 3), the eye-pieces were called 2-inch or 
l-inch, the necessary calculation (50 x 15 = 750 or 50 x10 = 500) 
is instantly made. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 105 


TABLE OF MAGNIFYING POWERS. 


- OBJEC- 
TIVES. EYE-PIECES, 
Beck’s 1 ea y; Beck’s 4 
lpowell’s 1 Se 4 Powell’s 3) Ross’s C. | Beck’s 3.) Powell’s i Beck ra Powell’s 5.] Ross’s F. 
Ross’s A. Ross’s B, Ross’s D. |” y 
nearly.* 
a 
is Focat LENGTH. 
B|t.e 
z Z | Qin. | 1iin.| lin. | Zin. Zin. | Lin. | Hefei, || geftne |) eer. 
4 Fy 
a zs Macnrryine Power. 
8 4 
ie 5 | 7% | 10 | 12 15 20 | 25 | so | 40 
COMBINED AMPLIFICATION OF OBJECTIVES AND 
EYE-PIECES. 
in. 
5 2 i) 10 15 20 25 30 40 50 60 80 
4 23 124 182 25 314 374 50 624 te 100 
3 31 162 25 334 412 50 662 834 100 1332 
2 5 25 374 50 624 75 100 125 150 200 
13 2) 334 50 662 832 100 1334 1662 200 2662 
1 10 |} 50 75 100 125 150 200 250 300 400 
=8| 12% 624 932 125 1562 1873 250 3122 375 500 
3 132 662 100 1331 1662 200 2662 3331 400 5332 
2) 15 7) 112% 150 1873 225 300 375 450 600 
4 20 |} 100 150 200 250 300 400 500 600 800 
| 25 | 125 1873 250 3124 375 500 625 7930 1000 
4 30 |f 150 225 300 375 450 600 750 900 1200 
§,| 333} 1662 250 3331 4162 500 6662 334 1000 13331 
t 40 200 300 400 500 600 800 1000 1200 1600 
1) 50 250 375 500 625 750 1000 1250 1500 2000 
2 60 300 450 600 750 900 1200 1500 1800 2400 
+} '7O }j 350 525 700 875 1050 1400 1750 2100 2800 
+ 80 400 600 800 1000 1200 1600 2000 2400 3200 
3 90 |} 450 675 900 1125 1350 1800 2250 2700 3600 
wo 100 500 750 1000 1250 1500 2000 2500 3000 4000 
+ 110 550 825 1100 1375 1650 2200 . 2750 3300 4400 
ay 120 600 900 1200 1500 1800 2400 3000 3600 4800 
is 1380 650 975 1300 1625 1950 2600 3250 3900 5200 
a 140 700 1050 1400 1750 2100 2800 3500 4200 5600 
7,|150 750 1125 1500 1875 2250 3000 3750 4500 6000 
ay 160 800 1200 1600 2000 2400 3200 4000 4800 6400 
z,|170 850 1275 1700 2125 2550 3400 4250 5100 6800 
is 180 900 1250 1800 2250 2700 3600 4500 5400 7200 
,| 190 950 1425 1900 2375 2850 3800 4750 9700 7600 
ab 200 |} 1000 1500 | 2000 2500 3000 4000 5000 6000 8000 
=| 250 |f 1250 1875 2500 3125 3750 5000 6250 7500 } 10000 
as 300 |i 1500 2250 3000 3750 4500 6000 7500 9000 } 12000 
z,|400 |} 2000 3000 4000 5000 6000 8000 10000 | 12000 4} 16000 
sb 500 |f 2500 3750 5000 6250 7500 } 10000 12500 | 15000 | 20000 
z2|600 |} 3000 4500 6000 7500 9000 } 12000 15000 | 18000 | 24000 
a 800 |} 4000 6000 8000 {10000 {12000 } 16000 20000 | 24000 32000 


* Powell and Lealand’s No. 2 = 7°4, and Beck’s No. 2 and Ross’s B = 8 magnifying power or 


respectively 2; less and , more than the figures given in this column. 


106 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Judging from past experience, it will probably be too much to 
expect that the desired change should take place all at once, and 
that the A, B, O, &c., or Nos. 1, 2, 3, &c., should forthwith be swept 
away, but we would venture to suggest that the power of the eye-piece 
should be indicated in the catalogues and elsewhere, as well as the old 
title, and if this were done we are sure that the latter would soon be 
wholly disused. 

The tables of magnifying powers issued by opticians are at 
present, in many cases, of a very misleading character, not so much 
from the fact that the objectives are underrated—a true +/,-inch being 
called a 1-inch—but that, according to the tables, one and the same 
eye-piece magnifies differently when it is used with different objec- 
tives ! 

We have accordingly compiled the annexed table of magnifying 
powers for ready reference. It includes all the more usual objectives, 
and the full series of eye-pieces of Messrs. Beck, Powell, and Ross. 
It will be noticed that the magnifying powers of the No. 1 or A 
agree in all three cases, those of the No. 2 or B slightly varying, 
being 8, 7°4, and 8. It would be an improvement if they could 
all be made 73, which would preserve the uniformity of the series. 
The No. 8 or C vary greatly, being 15, 10, and 12}. The No. 4 or 
D agree, whilst No. 5 or E are 25, 30, and 25. 

We think that an ideal series should run thus:—No. 1 = 5, 
No. 2 = 71, No. 3 = 123, No. 4 = 20, No. 5 = 30. 

With the exception of the 3, ,, and 4, all the objectives 
included in the table are actually constructed by English or foreign 
opticians. As objectives are, however, not uncommonly found to 
vary somewhat from the designated focal lengths, the figures for the 
3, z7, and +}, have been retained. 

The length of tube is assumed as usual to be 10 inches. 


Braham’s Microgoniometer.*—At a recent meeting of the Bath 
Microscopical Society, Mr. Braham described a microgoniometer for 
measuring the angles of crystals. “The body of the microscope-tube 
is formed at right angles. A rectangular prism is so adjusted that 
the plane of the hypothenuse is at an angle of 45 degrees to the axis 
of rotation. On bringing any crystal into the centre of the field, a 
fibre in the focus of the eye-piece is made to coincide with either of 
its edges so that the degrees passed through can easily be read. 
Thus, as the instrument measures a magnified image of the crystal, 
and the object itself is stationary, it will readily be seen that the 
angles of any crystal visible under the highest powers of the Micro- 
scope can easily be measured.” 


Watson's Sliding-box Nose-piece.—Messrs. Watson have recently 
contrived a sliding-box nose-piece to carry (1) the vertical illuminator 
(Fig. 16), or (2) the analyzing prism (Fig. 17) of the polarizing 
apparatus, or (3) the binocular prism. The application of an extra 
nose-piece in this form appears to be convenient. Experience must, 


* Engl. Mech., xxxiy. (1881) p. 277. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 107 


however, decide how far it is advisable to add to Microscopes focussing 
at the nose-piece, extra appliances tending to affect the delicate fitting 
of the fine adjustment. 


Fic. 16. 


Deby’s Screw-Collar Adjustment.—Mr. J. Deby suggests that the 
application of a worm-wheel and tangent screw to the screw-collar 
adjustment of objectives (Fig. 18) would 
be found more convenient than the usual Fie. 18. 
system for adjusting the corrections with 
accuracy. The device, as figured, would 
not permit the objective to be enclosed ¢ 
in the ordinary brass box; but, as sug- 
gested by Mr. Beck, the tangent pinion 
might be cut off short and provided with 
a slightly tapering square head upon 
which the milled head would fit when 
required. 


Number of Lenses required in 
Achromatic Objectives. * —Mr. W. 
Harkness discusses the number of 
lenses required in an achromatic objec- 
tive consisting of infinitely thin lenses 
in contact, in order that with any given 
law of dispersion whatever, the greatest possible number of light-rays 
of different degrees of refrangibility may be brought to a common 
focus. 

For any system of thin lenses in contact we have 

1 
a7 — 1) A, + ( —1) A.+ (@s — 1A; + ete. (1) 
the number of terms being unlimited. For a dispersion formula we 
write 


#= (0) (2) 
The form of ¢ (A) is unknown, but there will be no loss of gene- 


* Bull. Phil. Soc. Washington, iii. (1878-80) pp. 65-7. Smithsonian Mise. 
Collections, xx. (1881). 


108 SUMMARY OF CURRENT RESEARCHES RELATING TO 


rality if it is developed in a series arranged according to the powers 
of X. We, therefore, have 


B=atba™+ca™ + cr? + ete, (3) 


in which a, b, c, etc., are constants, and the number of terms may be 
taken as great as is desired. 
Let us also put 
C=A,@,—1)+ A,G = 1+ ArG, =—1)+ ete. 
D=A,}6, +A,b, + A; 2; + ete. (4) 
E= A,c, + A,c, + A, c,; + ete. 
F = A,e, + A, e, + A; e; + etc. 
etc. etc. etc. 


the number of these equations, and the number of terms in the right- 
hand member of each of them, being the same as the number of terms 
in the right-hand member of (8). Now substituting for the p’s in 
(1) their values in terms of the auxiliaries C, D, E, etc., of the equa- 
tions (4), we find 
= C+ Da" + EA 4 Fa + ete (5) 

Considering as the abscissa, and fas the ordinate, this is the 
equation of the focal curve. Its first derivative, with respect to f and 
A, is 

df =i =i 
= —f(mDan—1 + nEa—! + ete.), (6) 

which, as is well known, expresses for every point of the curve the 
tangent of the angle made by the tangent line with the axis of 
abscissas. The number of rays of different degrees of refrangibility 
which can be brought to a common focus will evidently be the same 
as the number of times that the focal curve intersects the focal plane. 
But the focal plane is necessarily parallel to the axis of abscissas ; 
and therefore the greatest possible number of intersections of the 
curve with the plane can only exceed by one the number of tangents 
which can be drawn parallel to the axis of abscissas. To find these 
tangents we equate (6) to zero, and obtain 


0 =mDa"—1+ nEA"—!1-+ ete. (7) 


As dX can never be either zero, negative, or imaginary, we have 
to consider only the real positive roots of this equation; each of 
which corresponds to a tangent. 'To make the number of tangents as 
great as possible, the quantities D, E, F, etc., must be independent of 
each other ; which will be the case when the right-hand members of 
the equations (4) contain as many A’s as there are powers of A in the 
dispersion formula (4). All the terms of (7) contain the common 
factor X"-". Taking it out we have 


—mD=nEA"—-”+ pF a-" + ete, (8) 


from which it is evident that the number of real positive roots in (7) 
will always be one less than the number of powers of A in(3). Hence 
we conclude that :— 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 109 


In any system of infinitely thin lenses in contact, the number of 
lenses required to bring the greatest possible number of light-rays of 
different degrees of refrangibility to a common focus is the same as 
the number of different powers of A contained in the dispersion 
formula employed. 

The method made use of in arriving at this result has been 
adopted, because it brings out clearly the geometrical relations of the 
problem. The result itself is evident from a mere inspection of 
equation (5), which cannot possess more real positive roots than it has 
independent auxiliaries, D, E, F, etc. 


Colour Corrections of Achromatic Objectives.*—The following 
abstract is published of a paper by W. Harkness :— 

1. From any three pieces of glass suitable for making a corrected 
objective, but not fulfilling the conditions necessary for the complete 
destruction of the secondary spectrnm, it will always be possible to 
select two pieces from which a double objective can be made that 
will be superior to any triple objective made from all three of the 

ieces. 
: 2. The colour correction of any objective is completely defined 
by stating the wave-length of the light for which it gives the minimum 
focal distance. 

3. An objective is properly corrected for any given purpose 
when its minimum focal distance corresponds to rays of the wave- 
length which is most efficient for that purpose. For example: in an 
objective corrected for visual purposes, the rays which seem brightest 
to the human eye should have the minimum focal-distance; while in 
an objective intended for photographic work the rays which produce 
the greatest effect upon silver bromo-iodide should have the minimum 
focal- distance. 

4. In the case of a double achromatic, the secondary spectrum 
(or in other words, the diameter, at its intersection with the focal 
plane, of the cone of rays having the maximum focal length) is abso- 
lutely independent both of the focal length of the combination, and 
of the curves of its lenses; and depends solely upon the aperture 
of the combination, and the physical properties of the materials 
composing it. 

5. When the focal curve of an objective is known, and the 
relative intensity, for the purpose for which the objective is corrected, 
of light of every wave-length is also known; then the exact position 
which the focal plane should occupy can be readily calculated. 

Incidentally, it may be remarked that in an objective corrected 
for photographic purposes the interval between the maximum and 
minimum focal distance is less than in one corrected for visual pur- 
poses. Hence a photographic objective has less secondary spectrum, 
and is better adapted for spectroscopic work, than a visual objective. 


Verification of Objectives.— The editor of the ‘ Northern 
Microscopist’ undertakes, for a nominal fee of 1s. 6d., to verify 


* Bull. Phil. Soc. Washington, iii. (1878-80) pp. 39-40. Smithsonian Misc. 
Coll., xx. (1881). 


110 SUMMARY OF CURRENT RESEARCHES RELATING TO 


objectives sent to him in regard to their amplifying power, working 
distance, absolute size of field, and real aperture.* 


Schultze’s Tadpole - Slide.t — This slide (or “ microscopic 
aquarium”) (Fig. 19) was devised for showing the circulation of the 
blood or the development of the blood-vessels in the larvee of the frog 
and triton. To one side of a thick slide is fastened by means of 


Fic. 19. 


Canada balsam a piece of another slide, cut as represented at A, and 
to the other side a second piece, of the shape seen at A’, so that there 
is a small cell in the centre of the slide, of the form shown in section 
in the figure. A cover-glass d closes the cell. 

To place the larva e in the cell, the cover-glass is taken off 
and the larva fished out of the water in a small watch-glass, and 
poured with the water into the cell. By manipulating with a brush, 
its head is brought into the hollow of the glass at A, and the tail 
placed on the sloping surface at A’. The cover is then quickly 
replaced, care being taken that the cell is full of water. The animal 
is excluded from air by the water, which, when it evaporates, can be 
replaced with the brush. In this way the circulation of the blood in 
the tail may be observed for hours at a time. 

Stokes’ Tadpole-Slide.t—Mr. A. W. Stokes fastens two pieces of 
a vulcanite ring (Fig. 20) to an ordinary slide so as to form an oval cell 
just large enough for the body of the tadpole, the tail projecting 
through an opening in the cell. Close to the latter a square of thin 


Fic. 20. 


cover-glass is cemented by Canada balsam so as to raise the tail to a 
level with the body. On each side of this are cemented two small 
oblong pieces of thin glass forming a cell for the tail to liein. A 
square of cover-glass over the body, and another over the tail, will 
keep the tadpole in place. 

* North. Microscopist, i. (1881) pp. 253-7. 


+ Thanhoffer’s ‘ Das Mikroskop und seine Anwendung,’ 1880, pp. 148-9 (1 fig.). 
+ Ann. Rep. Postal Mier. Soc., 1881, p. 13 (1 fig.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 111 


“Swinging Substage,” or “Swinging Tail-piece.”—At the time 
this contrivance was first introduced it was known asa “Swinging 
Tail-piece,” but since that time the term “substage” has been 
almost universally substituted. The earlier name is obviously, how- 
ever, the more appropriate, as it is not simply the substage which 
swings, but the mirror also, and we intend to adopt in future the 
expression “swinging tail-piece.” 


Value of Swinging Tail-pieces.—In addition to the opinions 
cited at p. 666 of Vol. I. (1881), the following has been published 
during the past year :— 

‘Mr. J. D. Cox, in the paper above referred to (see p. 102), 
considers that the swinging of the mirror-bar on the optical centre of 
the instrument is a positive improvement, but that the swinging of 
the substage is of very doubtful value. “In the former case several 
real advantages are gained. First, the mirror is kept at its proper 
focal distance from the object. Second, it may be swung above the 
stage for illumination of opaque objects. Third, it allows the instru- 
ment to be used for measuring aperture of object-glasses, by converting 
it into Smith’s ‘ Universal Apertometer.’* But when we ask for 
the advantages of swinging the substage with illuminating apparatus, 
it is difficult to find them. It is plain that we don’t want to swing 
the polariscope, the parabola, the dark wells, the Webster condenser, 
the wide-angled achromatic condenser, or the immersion illuminators, 
and could not if we would, for the form and mounting of these acces- 
sories is inconsistent with doing so. The question must practically 
be narrowed to the desirability of swinging the diaphragm and the 
low-angled achromatic condenser. Of course none of the flat dia- 
phragms can be swung in this manner, and no advantage seems to be 
found in the use of the sharp-nosed diaphragms with oblique light. 
The fact is that there are advantages in taking oblique light directly 
from the mirror ; for the chromatic fringes at the margin of the illu- 
mination often enable the microscopist to modify the light in a way 
to get increased resolution by turning the mirror so as to take the 
most lateral rays and those nearest the blue end of the spectrum. 
More range in quality of illumination can be got by the practised 
hand in this way than by the oblique use of the diaphragm. 

“In the use of an achromatic condenser, it must be a very low 
angle indeed which will work far enough from the bottom of the 
stage to allow much swinging to right or left, especially when we 
take into account the fact that the centering of the substage 
becomes more important when it is swung away from the axis of the 
instrument. 

“The centering arrangement of the substage will occupy so 
much lateral room that it can be swung but a little way before 
striking the stage. Again, any achromatic condenser of even 
moderate angle can be swung very little to right or left before its 
marginal rays will become parallel to the bottom of the slide con- 
taining the object under examination, and they then, of course, cease 


* See this Journal, ii. (1879) p. 775. 


112 SUMMARY OF CURRENT RESEARCHES RELATING TO 


to penetrate to the object or be of use for illumination. Still, 
again, experience seems to prove very conclusively that the most 
effective as well as the simplest arrangement for securing oblique 
light (otherwise than from the mirror alone) is by the prism, the 
traverse lens, the Wenham ‘half button,’ or other immersion sub- 
stage illuminators. These considerations lead strongly to the 
conclusion that the swinging of the substage is useless.” 

Ranvier’s Microscope-Lamp.*—This (Fig. 21) is described as 
consisting essentially of a metal globe, which covers the cobalt glass 
lamp chimney “and prevents the radiation of heat.” Four openings 
with plano-convex lenses conduct the light to four Microscopes. 
“The light can be so subdued that it is possible to work a long time 


Fic. 21, 


— Tu 7a 


— i T _— 
p IMTINTATT UOUDLUUUNUONDUONUOQSUOUNNOBULLUOUDDDOOUUOOTOUOTONONOTUUOOLONODUUn00)UDUIQOUOLODOOUIOOSICOONNONTTITG 


in the evening without straining the eyes, for which reason the lamp 
is preferable to all other kinds of illuminating apparatus. The 
cobalt glass is an essential feature, because the yellow-colour of the 
lamp-light is thereby obviated, and the sensation of white is produced. 
Certain shades of yellow and blue, as is well known, stand in 
relationship to each other as complementary colours, that is they 
produce white.” 

Hollow Glass Sphere as a Condenser,t—Mr. F. Kitton describes 
the effects of using a glass globe filled with water for the purpose of 
condensing light upon the object. This was used by some of the early 
microscopists,{ though it appears soon to have fallen into disuse, as it 

* Thanhoffer’s ‘ Das Mikroskop und seine Anwendung,’ 1880, pp. 73-4 (1 fig.). 

t Sci.-Gossip, 1881, pp. 274-5 (1 fig.). 

} Hooke, ‘ Micrographia,’ 1665 ; Ledermiiller, ‘ Mikroskopische Gemiiths- und 
Augen-Ergozung,’ 1762. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 113 


is not mentioned by Adams in his ‘ Micrographia Illustrata, 1771, 
or in his ‘Essays on the Microscope, 1787. Mr. Kitton tried it first 
with a }-inch objective upon Pleurosigma angulatum, using oblique 
light from the mirror ; the strize came out very distinctly. On removing 
the globe, the striz vanished and required a more oblique ray to 
render them again visible. Tried on Synedra robusta, it resolved the 
striz into beads. With a 2 inch, and not altering the previous position 
of the mirror, a ‘“‘black field” was obtained. The object Haliomma 
Humboldtii was seen with beautiful effect, appearing as though 
illuminated by intense moonlight with a slight green tinge and 
delightfully cool to the eye. It is also to be recommended with 
polarized light for softness of tint and impenetrable blackness of field 
when the prisms are crossed. A globe (6 inches in diameter) should 
be used, filled with a dilute solution of sulphate of copper (about 
- S$ ounce of saturated solution to 1 pint of water). The mixture must 
be filtered if ordinary water is used, though the intensity of colour 
is somewhat a matter of taste. The distance of the globe from the 
lamp should be about two or three inches; from the globe to the 
mirror about eight to twelve inches. 


Stein’s small Microphotographic Apparatus.*—Fig. 22 shows 
Stein’s microphotographic apparatus which, though small and simple, 
is said to answer its purpose completely. It 
is on the plan of Harting’s apparatus and Fig. 22. 
consists of a cone F which is inserted into ; 
the tube M of the Microscope instead of an Sim; 
eye-piece, a plate of ground-glass is fixed 
to the top, and on this the image can be 
focussed, the observer’s head being covered 
with a black cloth. The ground-glass plate 
is replaced by the prepared sensitive plate 
and the image can then be readily photo- 
graphed. 


Ranvier’s Myo-Spectroscope.t—In this 
simple and ingenious instrument (available 
for rapid superficial demonstrations) a prism 
is replaced by the muscular tissue, the trans- 
verse strie of the muscular bundles acting on white light like a 
grating and producing spectra. 

The muscles of the frog are the most suitable for observation, and 
especially the sartorius muscle, the bundles of which are parallel. 
The muscle having been taken with care from a living frog, it 
is dried for some hours in a stove at 40° C., after having been 
stretched with pins ona piece of cork. The muscle is then planed on 
both sides with a sharp scalpel, soaked in turpentine, and mounted in 
Canada balsam. 


* Thanhoffer’s ‘Das Mikroskop und seine Anwendung,’ 1880, p. 48 (1 fig.). 
4 Ranvier’s ‘Traité technique d’Histologie,’ Paris, 1878-80, pp. 316-19 
(1 fig.). 
Ser. 2.—Vor. II. I 


114 SUMMARY OF CURRENT RESEARCHES RELATING TO 


The myo-spectroscope is shown in Fig. 23. T’ isa tube 12 cm. long 
and 4 em. in diameter, blackened internally, and closed at one end by 


FG. 23. 


a diaphragm with a vertical slit /’ half a millimetre in breadth. At 
the other end is a stage plate with a central hole o (5 cm.): The 
preparation of muscle is placed in the clips in front of the latter hole 
and so that the axes of the muscular bundles are at right angles to 
the slit f’. On looking through the hole, whilst the instrument is 
directed to a light, spectra will be seen on the right or left of the slit. 

To observe the absorption-bands of hemoglobin, a second tube T is 
- added to the instrument, sliding over T’ and having a diaphragm with a 
large vertical slit f’’ in which is placed a tube S containing a solution 
of blood. Having first seen that the muscle givesa clear spectrum, 
T with S is replaced and the two absorption-bands of hemoglobin 
will be seen in the spectrum. 

As the spectrum produced by a grating is more extended according 
as the lines of the grating are closer together, we are led to investigate 
whether a muscle at the moment of contraction gives a wider spectrum 
than when at rest. The lower tendon of the sartorius muscle of a frog 
is separated from the tibia and the muscle stretched before a slit and 
it will be seen that on slightly stretching the muscle, the spectrum 
will be narrow and close to the slit. When the muscle is contracted 
the converse phenomena are produced, and when it is excited by a 
current and attains its maximum of contraction the width of the spectra 
and their distance from the slit are much angmented. 

The muscles of different animals thus examined do not give 
identical spectra. For example, those of the muscles of the frog are 
broader than those of the white muscles of the rabbit in the ratio of 
9 : 7. The transverse striation is therefore finer in the former case 
than in the latter. 


Standard for Micrometry.*—The Philosophical Society of 
Washington publishes the reply given by Dr. J. J. Woodward to the 
committee of the Microscopical section of the Troy Scientific 
Association who asked answers to the following questions : t— 

“1. Is it expedient at present to adopt a standard for micrometry ? 

2. If so, should the English or the metric system be employed ? 

* Bull. Phil. Soc. Washington, iii. (1878-80) pp. 22-4; Smithsonian Mise. 


Coll., xx. (1881). 
+ See this Journal, ii. (1879) pp. 154-9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 115 


3. What unit, within the system selected, is most eligible ? 

4, What steps should be taken to obtain a suitable standard 
measure of this unit ? 

5. How can this standard micrometer be best preserved and made 
useful to all parties concerned ? ” 

The reply was as follows :— 

“1. 1 am in favour of the adoption of a suitable standard for 
micrometry by the American Society of Microscopists at their next 
meeting. 

2. For this particular purpose I think the metric system offers so 
many conveniences that I favour its employment. 

3. The selection of an eligible unit within the system involves, it 
appears to me, two distinct questions: A. How shall the stage- 
micrometer be ruled? B. How shall the measurements made, be 
expressed in speech or writing ? 

A. The object of the stage-micrometer is chiefly to give values to 
the divisions of the eye-piece micrometer with the power used in any 
given case. It should be long enough to be used for this purpose with 
the lowest powers of the compound Microscope, and have a part of its 
length ruled sufficiently close to answer the same end with the highest 
powers. I favour the adoption of a standard scale a centimetre long 
ruled in millimetres, and one of these ruled in hundredths. I have 
used stage-micrometers ruled in thousandths of a millimetre, but 
regard such divisions as inconveniently close for this purpose. To 
measure in thousandths of a millimetre as the unit, which is very 
convenient in a large number of cases, the simplest way is to use a 
magnifying power that will make ten divisions of the eye-piece micro- 
meter exactly coincide with one-hundredth of a millimetre on the 
stage-micrometer. The glass eye-piece micrometer should have a 
scale a centimetre long ruled in one hundred parts. By increasing 
the power so that a larger number than ten of these divisions shall 
correspond to one-hundredth of a millimetre on the stage-micrometer, 
a unit of any degree of minuteness that may be required for any 
special work can be obtained up to the limits of distinct vision with 
the Microscope. 

B. But although I regard the hundredth of a millimetre as a very 
eligible dimension for the closest divisions of the stage-micrometer, 
when it comes to expressing the results of our measurement in speech 
or writing, I do not think it is convenient to use the hundredth of a 
millimetre as the unit of expression. It is too large, and the results 
of too many measurements would still have to be expressed in decimal 
fractions. The thousandth of a millimetre is much more convenient 
as a unit of expression, and I would advise that microscopists should 
agree to call this dimension a micron, and represent it in writing by 
the Greek letter 1. This dimension has already been adopted as the 
unit of expression by a number of European microscopists, who 
represent it by the same Greek letter, but call it a micro-millimetre. 
The term micron should, I think, be preferred because well known 
to scientific men other than microscopists, having for some time been 
used in expressing minute differences by those officially engaged in 

I 2 


116 SUMMARY OF CURRENT RESEARCHES RELATING TO 


preparing standard measures of length, and having been adopted by 
the International Metric Commission. I think it running an 
unnecessary risk of confusion to select any other than this well- 
recognized term for the dimension in question. 

4&5. To obtain a suitable standard stage-micrometer, I would 
advise each microscopical society to select one ruled, as above 
described, by any person in whom they have confidence, and to satisfy 
themselves by comparison of the several parts with each other, by 
means of the same part of the eye-piece micrometer, that the divisions 
agree among themselves. This is comparatively easily done; the 
real difficulty will be to determine whether the whole scale is really 
a centimetre long. To ascertain this, I would advise each micro- 
scopical society to send its standard micrometer to the Superintendent 
of the Coast Survey at Washington, with the request that he will have 
it compared with a recognized standard in the Bureau of Weights and 
Measures, and return it with a report of the error, if any. I have 
reason to believe that such requests would be promptly and courteously 
responded to. Each society should then preserve the standard thus 
obtained for the sole purpose of enabling its members to compare 
their stage-micrometers with it. I think this plan much wiser than 
to relegate the question to any one of the ingenious men who are 
endeavouring in this country, with considerable success, to make 
accurate rulings on glass, and I should anticipate better results from 
it than from the appointment of a special committee of the American 
Society of Microscopists to prepare a standard scale. 

In conclusion, I readily admit that so long as the English 
microscopists continue to express the results of their measurements in 
decimals of an English inch, there will be American microscopists 
who will do the same, either for all purposes or for particular work, 
and of course it is very desirable that these measurements also should 
be accurate. The stage-micrometers on this system in the market are 
usually ruled in hundredths and thousandths of an inch. The latter 
divisions are too wide to give values to the eye-piece micrometer with 
the higher powers, while the five-thousandths, ten-thousandths, or even 
finer divisions, ruled also on some of these micrometers, are incon- 
veniently close. I would advise the makers to rule such micrometers 
four-tenths of an inch long, divided into hundredths of an inch, one of 
the hundredths being subdivided into ten, another into twenty-five 
spaces. These latter spaces, each representing one twenty-five- 
hundredth of an inch, sufficiently approximate the hundredth of a 
millimetre to be used with equal convenience with the higher powers. 
The scale on the glass eye-piece micrometer, used with these stage- 
micrometers, should be, if specially made for the purpose, four-tenths 
of an inch long, divided into one hundred parts, each one two-hundred- 
and-fiftieth of an inch; but these divisions would so closly approximate 
those of the metric eye-piece micrometer proposed, that it might be 
used without inconvenience instead. Where it is thought worth 
while by a microscopical society to procure a standard scale of this 
kind, it should be sent to the Coast Survey Office for measurement, as 
in the case of the metric scales.” 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 117 


Rogers’ Micrometers.— Prof. W. A. Rogers, of Cambridge, U.S.A., 
recently offered, as we announced,* to present a ruled stage micro- 
meter to any one who would undertake to examine its divisions and 
publish the results. Mr.T. 8. Bazley having accepted the proposal, 
now details the result of the investigation.t ‘“ Placed on the stage, 
and viewed with a two-thirds objective, and a dark field, the ruled 
lines, which are not filled in with a dark pigment as is common, 
sparkle like streaks of diamonds; and under this illumination a 
singular appearance is noticed. Insome of the lines a slight internal 
splintering of the glass has apparently followed the course of the 
ruling-point, giving an effect of deeper cuts in certain places. But, 
as this effect is invisible with a bright field, and as there is certainly 
no variation in the width of the several lines, it probably arises solely 
from the nature of the glass; and the more so, as these apparently 
deeper cuts do not often extend for the entire length of a line, and 
sometimes occur side by side for a few lines. 

“The micrometer is of the ordinary 3 by 1 size. The ruled portion 
is a centimetre in length, and contains 1000 spaces, subdivided at 
every fifth and tenth, the lines being thus 0:01 mm. apart. The width of 
the band, neglecting those lines that project, is 1-375 mm. Every 
tenth line is1°6 mm. long, and the principal spaces of 6:1 mm. are 
subdivided by a shorter pro- 
longation of the fifth lines, Fig, 24. 
which measure 1°55 mm. 
These measurements are the 
average only, for the lengths 
of the individual lines vary a 
few thousandths of a milli- 
metre, and the lower edge of 
the band is not consequently 
strictly in one straight line. 
The terminations of the lines 
at the upper edge, indepen- 
dently of those projecting at 
every fifth and tenth, are not 
in the same straight line 
either. These deviate in a 
symmetrical manner; four 
lines between two long ones 
having their ends equal and straight, while the ends of the next four 
form a gentle convex curve. All the lines at this, which may be con- 
sidered the reading edge of the band, are terminated by singular 
hooks, suggestive of the curved handle of a walking-stick (see Fig. 
24); they differ somewhat in size and character, but have all the 
same direction, and are probably due to the stopping, lifting, and 
reversal, of the cutting diamond. 

“The objectives used were a series by several makers (dry, as well 
as immersion adapted to various media) up to Zeiss’s L, equivalent to 


* See this Journal, i. (1881) p. 678. 
+ Engl. Mech., xxxiv. (1881) pp. 341-2 (1 fig.). 


118 SUMMARY OF CURRENT RESEARCHES RELATING TO 


sz; the lines of the band being well defined under all of them; 
and the eye-piece micrometer, Jackson’s form, and a small spider-line 
micrometer. -The former depends a good deal for its result upon an 
estimation to tenths of its graduations, and can hardly be susceptible 
of the accuracy which should be attained with a well-made ‘ wire 
micrometer.’ The latter was therefore adopted and provided with 
additional draw-tubes, for use, either as an eye-piece in the usual 
manner, or in the substage, giving an aerial image of the spider-lines 
as proposed by Dr. Pigott.* This latter method, however, so far as 
my own experience goes, is more ingenious than effective ; principally 
because all vibration of the micrometer in that position is magnified 
by the whole power of the Microscope. There is one advantage 
possessed by Jackson’s in the spring action, which moves the whole 
scale, and consequently its zero point, with extreme nicety. In the 
spider-line micrometer, one wire is generally fixed, and the only way 
to bring a given point of an object under the Microscope to coincide 
with that wire is by the screw action of the stage, which, with a high 
power, is far too sensitive and rapid. To obviate this difficulty, a 
traversing movement to the extent of a fifth of an inch, controlled by 
a screw of fine pitch, was added to the small micrometer between its 
screw-plate and draw-tube. By this means any given line on the ruled 
band, after being brought approximately into position with the stage 
movement, could be accurately bisected by the fixed wire of the micro- 
meter. The objectives finally selected were a + for the measurement 
of the principal subdivisions of 0°05 mm. each, and a 1, imm. for the 
close spaces. These objectives gave the most convenient decimal values ; 
the former by suitable adjustment of the draw-tube giving *00025 mm. 
as the equivalent of one division of the micrometer divided head (50 
divisions to one turn); and the latter -0001 mm. Both glasses were 
by Beck, and their magnifying powers, with the positive eye-piece 
employed, were 950 and 2500 respectively. Of course the eye-piece 
could be changed at pleasure, without altering the ratio of scale to 
image. Thefine movement of the Microscope employed is on its 
main tube; its action propels or withdraws the nose-piece, thus 
possibly interfering with the value, as adjusted by the lengthening 
draw-tube, of the micrometer scale in terms of a given unit. It 
proved, however, by actual experiment, using a power of 1000 
diameters, that an alteration of the fiftieth of an inch in the distance 
from eye-piece to stage, made no perceptible change in the ratio 
between the micrometer in the eye-piece and that on the stage, so any 
supposed error in measurement from this cause may be dismissed as 
visionary. All kinds of illumination were tried, the preference being 
given to that described [in this Journal, I. (1881) p. 666], using 
the concave mirror without condenser, at an obliquity of about 40°, 
and a thin metal plate attached below the stage, at such an angle 
that no rays from the lamp can reach the object, except by reflection 
from the inclined mirror. With the light so directed, each line of 
the band was evenly divided, longitudinally, into a dark half and a 
light half, giving much facility for the exact superposition of a 
* Mon. Micr. Journ., ix. p. 3. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 119 


micrometer-wire upon the centre of the image of any line. In 
examining the spaces seriatim, there was some risk of losing count, 
and as a means of reference, a scale of figures, photographed by 
Mr. J. Mayall, jun., to the exact length of a centimetre, was pasted 
at the upper edge of the band, so that the principal graduations of 
the latter could be identified with a low power. 

“ Coming, at last, to the examination of the plate ruled by Prof. 
Rogers, perhaps its most distinguishing feature is the perfect straight- 
ness and similarity of the individual lines. The stage micrometers 
commonly met with are so deficient in this respect, that it is impos- 
sible to obtain equal distances from different parts of the same two 
lines of the scale. But with the rulings of Prof. Rogers no such 
inequality exists. The spider-lines at the eye-piece may be set to any 
interval of lines on his micrometer, and the scale will rigidly indicate 
the same distance at any other part of the band, whether above, 
below, or on either side the position first selected. As to the actual 
width of the lines themselves, I make it to be ‘001 mm. almost 
exactly. After all these precautions for the study of this micrometer, 
perhaps a list of small, though definite, errata may be looked for ; but 
I have carefully verified the principal intervals of the band, and a 
large number, taken at hazard, of the 1000 close spaces, and have 
detected no discrepancies whatever. The only possible criticism that 
occurs to me is that the projecting lines at the reading edge are 
perhaps needlessly Jong, and that if the ‘ walking-stick hooks’ could 
be transferred to the other side of the band, it would be an improve- 
ment. I believe the ruling to be as accurate as mechanical means. 
can produce; and though there is no means of deciding whether the 
spaces are true subdivisions of the French metre, the perfection of 
the subdivisions themselves is a tolerably sure guarantee that the 
Professor took every care to verify his unit to begin with.” 


Section of “Histology and Microscopy” at the American 
Association.—At the last meeting of the American Association for the 
Advancement of Science, a section of “Histology and Microscopy,” in 
place of the previously existing sub-section of Microscopy, was 
established, to rank on the same footing as the other sections of the 
Association, and to be represented on the Standing Committee, its 
Chairman being ex officio a Vice-President. 


Structure of Cotton Fibre.*—Dr. F. H. Bowman has published 
an elaborate investigation into the structure of cotton fibre, in which 
he gives a general account of the plant botanically, and deals with the 
typical structure of a cotton fibre, both in regard to the mechanical 
arrangement of its ultimate parts, and chemically. A full consideration 
is given to the variations from the type structure which are found to 
exist and the extent to which any variation in the ultimate fibre may 
affect its use in the manufacturing process. 

The book is illustrated with plates of typical and other cotton 


* Bowman, F. H., ‘The Structure of the Cotton Fibre in its relation to 
technical applications,’ xvi. and 211 pp., 5 figs. and 12 pls. 8yo, Manchester, 
1881. 


120 SUMMARY OF CURRENT RESEARCHES RELATING TO 


fibres and with coloured plates, showing their appearance when dyed 
with turmeric yellow, indigo blue, &c. 

The value of the Microscope with ordinary and polarized light, 
and with dyed and undyed fibres, is throughout made a special feature, 
and the book is to be welcomed as a noteworthy addition to the, at 
present, very scanty literature relating to the practical applications of 
the Microscope to manufactures. We should imagine that both silk 
and woollen manufacturers would be benefited by similar treatises on 
silk and wool. 

The limit of microscopical vision is, on pp. 156-7, treated as 
synonymous with the limit of microscopical resolution, and in any 
future references to the subject care should be taken to show that the 
latter refers exclusively to the power.of distinguishing as separate two 
lines or other objects close together, the limit of which is half the wave- 
length in the medium employed x sin. uw, whilst the vision of isolated 
minute objects is only limited by the sensitiveness of the particular 
observer's retina, the distribution of light, &c. Limit of “ visibility ” 
is distinct from the limit of “ visible separation.” 


g. Collecting, Mounting and Examining Objects, &c. 


Durable Preparations of Microscopical Organisms.*—Professor 
G. Entz describes the method used by him for mounting microscopical 
organisms, Protozoa, Rotifera, &c., preceded by an historical review 
of the processes hitherto adopted. 

Ehrenberg + used a dry process which answered well only for 
certain objects. Its use may be somewhat extended by soaking the 
dried preparation in 1 part distilled water, 1 part glycerine, and (in 
a large quantity) 1-2 drops of picric acid. The shrivelled parts 
swell out and look very life-like. Amongst the organisms capable 
of being so treated are the Volvocineze, Chlamydomonads, the lori- 
cated Huglene (£. acus and E. Spirogyra) Peridines, the tests of 
Rhizopods, tubes of Melicerta, Ciliata with resisting cuticles (as 
Stentor igneus, Epistylis plicatilis, and fine chitinous elements, such as 
the masticatory apparatus of Rotifera and small Nematodes. The 
protoplasmic parts of organisms are of course entirely lost by this 
method. 

Later still, Du Plessis { suggested glycerine coloured with chro- 
mate of potash, and Duncker § in 1877 exhibited Rotifers, Protozoa, 
and Alge, which were highly commended by such authorities as 
Cohn, Stein, and Leuckhart, and which showed the fine parts in a 
most wonderful manner. Unhappily they were not permanent. In 
a few weeks brown oily drops began to make their appearance in the 
fluid, and ultimately the protoplasm also browned, so that they are 
now useless. Duncker never published his method, but the author 
considers it probable that the basis of the fluid he used was rectified 


* Zool. Anzeig., iv. (1881) pp. 575-80. 

+ Abh. K. Akad. Wiss. Berlin, 1835, p. 141; 1862, p. 39. 
{ Arch. f. Naturg., 1864, ii. Band, p. 162. 

§ See this Journal, i. (1878) p. 221. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 121 


pyroligneous acid, which, allowed to run in under the cover-glass 
in small quantities, killed and fixed the organisms in their natural 
form. 

After referring to the methods suggested by Certes,* Biitschli,t 
and Thanhoffer and Davida,t the author describes that which he 
has adopted in the hope of obtaining the same beautiful results as 
Duncker, but at the same time more durable. 

“ According to my experience, various means, long known, are 
adapted for fixing the smallest and most delicate organisms; for 
instance, rectified pyroligneous acid, the ‘liqueur salin hydrargy- 
rique’ of Blanchard, in the mixture which Arnold Lang recommends 
for preserving marine Planarians, § and which has been also used by 
Paradi for fixing fresh-water Turbellarians with the best results; 
also picric acid ; and lastly, what Paul Mayer has so strongly recom- 
mended || for the lower animals, viz. picro-sulphurie acid, which 
certainly should have the preference over the others. All these 
media (the list of which is by no means exhausted), kill microscopical 
organisms instantaneously, without destroying their organization. 
Flagella and cilia, the suctorial disks of the Acinete, and even the 
fine pseudopodia of the Heliozoa can be fixed as well as the pedicel of 
the rapidly-jerking Vorticelle. Also the muscle of the pedicel, the 
contractile vacuoles, and the cesophagus and digestive vacuoles. 
Huglence and Amebe may be fixed in their various changing shapes. 
Rotifera die mostly with their peristomes moderately withdrawn, and 
Vorticelle the same; but examples may be obtained from COarchesium- 
and Epistylis-stems, which are fixed in the act of lively rotation. 
Infusoria are fixed in the same life-like state, in the act of fission or 
conjugation, and Vorticelle in the bud form of conjugation. The 
nucleated elements also come out very prominently, even the nucleolar 
capsules can be splendidly preserved for further study, and their 
striation retained. Spongille, Hydre, small Nematodes, Tardigrades, 
delicate insect larvee, and ciliated cells (e.g. of the gills of mussels) 
can be excellently fixed and preserved. To obtain durable prepara- 
tions, however, it is absolutely necessary to remove the fluid which 
has completed its work in the process of fixing, as it might injure the 
fine organisms by longer action, afterwards placing the preparation in 
a fluid which is suited to it. 

“ My procedure is essentially the same as that which Paul Mayer 
used for treating the lower marine animals with picro-sulphuric 
acid. ; 

“JT place the Protozoa and other microscopical organisms with 
the Algz, sediment, or other objects to which they are affixed or 
between which they move, with some water in a watch-glass, then 
drop in a few drops of the fixing fluid, which I allow to act only 1-2 
minutes. I then pour off the fluid carefully, or simply lift the 

* Comptes Rendus, Ixxxviii. (1879) p. 433. See this Journal, ii. (1879) 
pp. 331 and 763. 

t Zool. Jahresber., 1879, p. 173. 

{ Thanhoffer, L. v., ‘Das Mikroskop und seine Anwendung,’ 1880, p. 110. 


§ Zool. Anzeig., i. (1878) p. 14. See this Journal, i. (1878) p. 256, 
|| MT. Zool. Stat. Neap., ii. (1880) pp. 1-27. 


122 SUMMARY OF CURRENT RESEARCHES RELATING TO 


preparation out with a pencil or scalpel, in order to transfer it at 
once into a larger quantity of alcohol, which must not be too strong. 
Half an hour is usually enough to withdraw the fixing fluid and 
replace it by alcohol, in which it may remain a longer time without 
damage. For removing the chlorophyll colouring-matter of many 
Infusoria, and also the Algee in the preparation, a longer stay in 
alcohol is of course necessary, replacing it by clear alcohol when it 
has become coloured. 

“Microscopical organisms thus treated are ready to be at once 
mounted in dilute glycerine (1 part of distilled water to 1 of 
glycerine). But colouring must not be neglected. Among the 
colouring materials commonly used (carmine, hematoxylin, and various 
aniline dyes), carmine certainly is to be preferred, because it is 
not bleached in glycerine, and moreover does not colour everything 
with one tint like the aniline dyes, but principally the nuclear ele- 
ments. Preparations transferred from alcohol to carmine are mostly 
coloured sufficiently in 10-20 minutes, only loricated forms as 
Euglena, Spirogyra and species of Phacus, the Peridinex, &c., require 
several hours to make their nuclei sufficiently prominent. Before 
being transferred into dilute glycerine, the preparations must of 
course be put into distilled water, and remain until the yellow picric 
acid is drawn out, and the preparation shows a nice rose colour. 

“ By the above process beautiful and instructive preparations are 
obtained, which when carefully mounted show no further change. I 
have a fairly considerable collection of different Protozoa which have 
not altered in the least for 6-7 months, and are adapted both for 
demonstration and for detailed study.” 


Preparing Anthers.*—J. Rataboul proposes an improved method 
for preparing anthers, to show the fibrous cells of their walls. 

The ordinary method of preparation is to leave the anthers in 
water until the walls swell, and by triturating with a quill to loosen 
some shreds of tissue. If any cells are found the tissue must be 
washed with care to remove pollen-grains and air-bubbles. These 
manipulations are long, delicate, and difficult, and are not always 
successful; and the author’s method is to place the anthers in 90° or 
100° alcohol for 4-5 minutes, triturating grosso modo, and immediately 
putting it in distilled water. The cells open as if by enchantment, 
the pollen-grains are readily detached, the alcohol dissipates the 
air-bubbles, and by this process a much larger portion of the anthers 
can be obtained for examination. 


Herpell’s Method of Preparing Fungi for the Herbarium.j— 
G. Herpell announces some improvements on his method previously 
published, and which we have already described.} 

In the method proposed for the preservation of the fleshy parts he 
has no improvement to suggest; but in the preparation of the spores 
various slight emendations have presented themselves, 

* Bull. Soc. Belg. Micr., vii. (1881) pp. exliv—v. 


+ SB. Bot. Ver. Prov. Brandenburg, June 24, 1881. 
} See this Journal, i. (1881) p. 136. 


‘Sr 


jes: 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 123 


The fixing of the coloured spores with lac on white paper answers 
completely ; but, in the case of the Leucospori, only those of species 
of Russula and Lactarius unite firmly with the resin of the lac. On 
the other hand, the mode of fixing the white spores on blue cardboard 
simply with gelatine appears to answer in all cases ; but the solution 
should be somewhat more dilute than previously stated. The best 
fluid is a warm solution of 1 part gelatine in a mixture of 150 parts 
water and 150 parts alcohol. This answers with species of Russula 
and Lactarius, while with Agaricus (Collybia) radicatus so concentrated 
a solution as 1 part gelatine in 30 parts water is necessary. The 
writer gives a list of a number of species, with the strength of solution 
required in each case. Some spores can be fixed on blue cardboard 
by the use of pure water only. In some cases, again, it is necessary 
to heat the solution strongly. Agaricus (Collybia) maculatus, A. (C.) 
velutipes, and Marasimus peronatus require a different treatment, which 
is described. 

The author found the same results with the fluid recommended by 
Patouillard (2 parts mastic in 15 parts ether) as with the lac; the 
resin does not in all cases combine well with the white spores. 
The ether has some advantages in penetrating the paper more rapidly 
and completely, but, on the whole, Herpell prefers the use of 
alcohol. 


Dissociation of Gland-Elements.*—Cauderau finds boiling the 
mucous membrane of the stomach in a solution of nitrate of soda a 
very good process for isolating the glands and gland-elements, but the 
constituent parts of the tissues become too brittle. This defect can be 
obviated by a previous immersion of some minutes in osmic acid. 
The cells will then remain admirably preserved after boiling for three 
hours, but can scarcely be stained at all. The following combination 
is therefore recommended :—One part of Miiller’s fluid is diluted with 
two parts of water and about 30 to 40 grammes of the sodic nitrate is 
dissolved in a litre of the mixture. Boiling for three hours in this 
compound is sufficient to break up the mucous membrane of the 
stomach. ‘The maceration, besides acting on the glands, extends to 
the muscular coat. 


Method of Preparing and Mounting Soft Tissues,t— The con- 
clusions arrived at with regard to the structure of the nervous centres 
by means of the successive action of bichromate of potash and nitrate 
of silver will certainly receive confirmation from this method, which 
we owe to Professor C. Golgi. It has the double advantage of 
enabling us to stain the nerve-cells black within a given time, and of 
turning out preparations which may be kept for a long period in the 
ordinary mounting media. 

The pieces of tissue are hardened to the necessary degree in 
Miller’s fluid, or in solutions of bichromate of potash, whose strength 


* Gaz. méd. de Paris, No. 45, pp. 577-8. Cf. Jahresber. Anat. u. Physiol., 
Vili. pp. 13-14. 

+ Rendiconti R. Istit. Lombard., xii. pp. 206-10. Cf. Jahresber. Anat. u. 
Physiol., viii. pp. 12-13. 


124 SUMMARY OF CURRENT RESEARCHES RELATING TO 


is gradually increased from 1 to 24} per cent. The pieces must not 
be more than 1 to 2 em. thick, a large proportion of fluid must be used, 
and it must be frequently changed. In from 15 to 20 days the pieces 
are put into corrosive sublimate solution } to 4 per cent. in strength. 
The reaction requires at least 8 to 10 days, and during this time 
the liquid must be daily renewed. The pieces gradually change 
colour and acquire the appearance of fresh brain-substance. They may 
be allowed to remain even for a longer time in the solution, which 
serves at the same time to harden them. Sections which are to be 
kept must be repeatedly washed, else crystals and other deposits appear 
upon them and alter the appearance under the Microscope. They keep 
admirably well in glycerine, which is perhaps better for the purpose 
than Canada balsam and dammar. By this method the ganglion-cells 
with their processes are acted upon; their nuclei are often left visible ; 
the elementary constituents of the walls of the vessels, and especially 
the smooth muscular fibres (muscle fibre-cells), are also brought out. 
Golgi reports having had good results from the application of this 
treatment to the cortex of the cerebrum, negative results in the case 
of the spinal cord, and but slight success with the cerebellum. The 
author calls the reaction an apparently black one, inasmuch as the 
elements on which it has taken effect appear white under surface 
illumination, and black only by transmitted light. 


Preservation of Anatomical Specimens.*— L. Gerlach recom- 
mends the glycerine process of Van Vetter, which has been some- 
what modified, firstly by Stieda and then by Gerlach himself. Stieda’s 
recipe is as follows :—Make a mixture of 6 parts of glycerine, 1 of 
brown sugar, and } part of saltpetre ; Gerlach uses 12 instead of 6 parts 
of glycerine. The preparations are cleaned and laid in this liquid, in 
which they remain from three to six weeks, according to their size. When 
taken out they have a dark-brown colour and are quite firm; they are 
then hung up in a chamber of the temperature of 12°-14° R. (59° to 
634° Fahr.). In the course of eight to ten days they become soft and 
flexible, but must be allowed to hang from two to six months longer, 
to be available for demonstrations. The more glycerine used, the 
lighter in colour the preparations remain. The method is best applied 
to preparations of articulations, to sense organs (eye, ear), larynx, &e. 
The formation of a crystalline precipitate, which sometimes appears 
in the drying, is met by the increase in the proportion of glycerine 
and a diminution of the saltpetre and sugar. If large objects are to be 
set up, such as whole extremities with their muscles, or the thorax 
with the ligaments dissected, pure glycerine is preferable to the cheap 
crude article, for specimens turn out whiter and less hard in it, 
Gerlach has used it for temporal bone with tympanum and auditory 
ossicles, and obtained valuable preparations which may be employed 
with great success to demonstrate the transmission of waves of sound 
from the tympanum to the labyrinth. 

Barff’s Preservative for Organic Substances.—A new preserva- 
tive applicable to all animal and vegetable substances has been 


* SB. phys-med. Soc. Erlangen, July 28, 1879. Cf. Jahresber. Anat. 
u. Physiol., viii. pp. 112-13, and Jahresber. (Virchow and Hirsch) for 1879, p. 2. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 125 


patented by Professor F. 8. Barff. It is a compound prepared by 
mixing boracic acid with glycerine. The former is dissolved in the 
latter by the aid of heat, the solution taking about four or five hours, 
care being taken, however, that the temperature employed shall not be 
SO excessive as to decompose the glycerine. 'To such solution or com- 
pound a further quantity of boracic acid is added from time to time 
until the boracic acid ceases to be dissolved. The compound resulting 
when allowed to cool, is solid, and is called by the patentee 
boroglyceride. 

In order to employ the compound, a solution is prepared in water, 
alcohol, or other suitable solvent, and the organic substances to be 
operated upon, either immersed in or impregnated with such solutions. 
Solutions may be prepared of various degrees of strength; but 
Professor Barff finds that a solution consisting of about one part by 
weight of the compound and forty parts by weight of water will give 
good results ; other proportions may, however, be adopted for special 
purposes. Solutions of the compound may be applied to the preser- 
vation of all organic substances either animal or vegetable. 


Injection-mass.*—L. Teichmann injects blood-vessels and lym- 
phatic vessels with a mass which is fluid when cold; it is made with 
finely powdered materials and linseed-oil varnish up to the consistency 
of putty, and altered to that of honey or syrup as required, by volatile 
liquids (such as ether and carbon disulphide). Prepared chalk, 
zine white, &c., may be used, coloured with cinnabar, ultramarine, 
chrome yellow, &c. Ordinary hand-pressure is not powerful enough, 
so Teichmann makes use of syringes, such as those for injecting gutta- 
percha, in which the piston is impelled by a screw arrangement. 

In this way, even the finest and most elaborate ramifications of 
the vessels may be readily and with certainty filled. The mass soon 
stiffens, partly owing to transudation, partly to evaporation of the ether, 
so that it does not ooze from vessels which may be cut through; it 
remains soft for a certain time and is as hard as stone when the 
preparation is finished. The advantages of this method are obvious. 


Imbedding Delicate Organs,t—L. Frédéricq describes a method 
by which pieces of tissue or organs, such as brains of small animals, 
livers, kidneys, &z., are so thoroughly impregnated with paraffin that 
they retain a firm consistence, do not shrink up, and keep as well as 
the best casts of the organs. The tissue or organ is hardened by 
placing in alcohol, first dilute, then absolute, for several days, is then 
laid for several days in oil of turpentine, until transparent, when it 
is transferred to paraffin melted in a water bath, and kept there at 
a temperature of about 55° C. (it must not exceed 60°), for from two 
to eight hours, according to the size of the object. It is removed and 
dried while hot in a current of steam, by blotting-paper or otherwise, 
and finally allowed to cool. 


* SB. Math. Kl. Krakau. Akad., vii. pp. 108-58. Cf. Jahresber. (Virchow 
and Hirsch) for 1879, p. 2. 


+ Gaz. méd. de Paris, 1879, No. 4, pp. 45-6. Cf. Jahresber. Anat, u. Physiol., 
Vili. p. 12. ; 


126 SUMMARY OF CURRENT RESEARCHES RELATING TO 


‘Katsch’s Large Microtome.*—In this instrument (Fig. 25), a 
stand, similar to that of a sewing-machine, supports a tray, across 
which, in a diagonal direction, a small ledge is fixed. This is inclined 
rather outwards, and on one end of 
it the cutting knife rests, so as to 
move steadily against the micro- 
tome plate which rises a little above 
the tray, and surrounds the pre- 
paration. The plate itself is at 
the end of a hollow cylinder fixed 
to the tray, in which a massive 
metal cylinder can be raised and 
lowered by a screw underneath. 
There are three knobs on the upper 
part of this cylinder to fix the sub- 
stance in which the preparation is 
imbedded. 

When the latter is cooled (which 
is done by pouring water into the 
tray) the section can be made. 

A special advantage of this form 
- of instrument is that sections can 
= be cut under water, and that the 
screw may be fixed by means of a 
small click to the 3,5, mm. In 
turning the screw the click is caught at every 5,55 mm., and gives 
an audible signal. 


—e 


i 
1) 


f q 
Y Wi 


Cox’s ‘Simple Section-cutter for Beginners.’ {—In this, economy 
and simplicity have been carried to at least their furthest practicable 
limits, as the basis of the instrument is a sewing-machine cotton-reel, 
and a Perry’s music binder. The cost does not exceed 2 or 3 pence. 


Cutting Sections of very small Objects.{—H. Strasser adds 
from 3 to 4 parts of tallow to the imbedding mixture recommended by 
Kleinenberg (spermaceti 4 parts, castor-oil 1 part), and in order to be 
able conveniently to arrange very small objects for cutting sections in 
any required position, he places them in the mass while this is still 
warm, between plates of mica; the temperature must never exceed 
45° C. After cooling the mica plates may be readily separated from 
the mass, which has the form of a thin sheet, and contains the object ; 
it may be then fixed with heated pins in the desired position upon a 
block of a substance not easily melted. 


Mounting in Balsam.§—Dr. C. Seiler, in a paper contrasting 
glycerine and balsam as mounting materials, gives the following as 
a desirable modification of the old process of mounting in various 


* Thanhoffer’s ‘Das Mikroskop und seine Anwendung,’ 1880, pp. 96-7 (1 fig.). 

+ Ann. Rep. Postal Micr. Soc., 1881, pp. 12-13 (1 fig.) 

t Morphol. Jahrbuch, v. (1879) p. 243. Cf. Zool. Jahresber. Naples, i. (for 
1879) p. 35. 

§ Proc. Amer. Soc. Micr., 1881, pp. 60-2. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 127 


media, whereby the disadvantages attendant upon the use of balsam 
are removed, so that it becomes the preferable method. 

Take a clear sample of Canada balsam and evaporate it in a water 
or sand bath to dryness; i.e. until it becomes brittle and resinous 
when cold. Dissolve this while warm in warm absolute alcohol 
(Squibbs’), and filter through absorbent cotton. Place the section, 
after it has been stained, in weak alcohol (about :60), and allow it 
to remain in a few minutes, then transfer it to -80, °95, and finally 
to absolute alcohol, in which it should remain a few minutes also. 
Then transfer it to the slide (which has been slightly warmed above 
a spirit-lamp so as to remove all moisture), drain off all superfluous 
alcohol, and place a drop of the alcoholic balsam solution on the 
specimen. In a few seconds the latter will become transparent, when 
it may be covered, and set aside to dry. In.damp weather, or when 
breathed upon, a milky edge will be noticed on the drop of balsam, 
which is caused by minute globules of water, which, however, may 
readily be dispelled by the application of a little heat to the under 
side of the slide. It will be seen that by the gradual dehydration of 
the specimen, the danger of distortion of the histological elements 
is materially diminished ; that by the omission of any clearing agent 
the shrivelling is avoided as well as the solution of fat in the cells 
prevented, for cold alcohol alone will not dissolve fat ; and finally by 
evaporating the balsam to dryness all other constituents except the 
pure balsam are driven off, so that the danger of crystallization is 
avoided. 


Mounting in Glycerine,*—Dr. 8. R. Holdsworth finds the follow- 
ing plan to be efficacious in avoiding the difficulty found in getting rid 
of the surplus glycerine when it has passed beyond the cover-glass, 
He puts a very small drop of glycerine upon the object, just sufficient 
that when the cover-glass is applied it will not extend to the margin. 
A solution of Canada balsam in chloroform or benzoline is then run 
in to fix the cover-glass, and not being miscible with the glycerine, an 
air-space is formed between the two fluids which has not been found to 
be detrimental. The slide can be finished with a ring of balsam or 
other cement. 


Smith’s Slides.j—The Editor of the ‘ American Monthly Micro- 
scopical Journal’ writes:—‘“ Mr. J. Lees Smith, of this city, has 
prepared some very attractive slides in this manner: the glass slips 
are first coated with photographer’s ‘ granite varnish’ by flowing, just 
as a plate is coated with collodion in photography. This coating of 
varnish gives the slide the appearance of finely ground glass. It is 
then placed on the turntable, and, by means of a knife-blade, the 
varnish is entirely removed from a circular spot in the centre, just 
large enough for the cell in which the mount is to be preserved. 
The preparations we saw were mounted in glycerine, and the clear 
and transparent cells were made of Brown’s rubber cement, which Mr. 
Smith regards as a most excellent cement, especially for glycerine 


* Ann. Rep. Postal Micr. Soc., 1881, p. 11. 
t Amer. Mon. Micr. Journ., ii. (1881) p. 179. 


128 SUMMARY OF CURRENT RESEARCHES RELATING TO 


mounts. Imagine a slip of ground glass with a transparent spot in. 


the centre, upon which objects can be mounted, and one can thus 
form an idea of the appearance of these slides.” 

Spring Clip Board.*—Mr. W. Stringfield gives the accompanying 
sketch (Fig. 26) of the spring clip boards he has had in use for some 
time, and which, for reducing the breakage of thin glass covers to a 
minimum, economy of construction, and convenience of moving, far 


Fic. 26. 


surpass, he considers, any arrangement that has come under his notice. 
They are made of mahogany, but of course pine or other wood can be 
used. All, however, should be baked previously to finally planing up. 
A is a piece of mahogany 12 x 7} x ? inches; B_ two strips, 
each securely fastened down the centre of the base board A by 
eleven screws; CC pieces of watch or crinoline steel, 38% inches 
long, 2 inch wide, with a hole punched in either end to allow of a 
small brass pin passing through for securing the pressers; D D small 
pieces of phial corks; EK E EE four screws fitting in corresponding 
holes drilled in the bottom of each board, thus allowing a number to 
be placed one on the other without injury to the slides, and admitting 
a free current of air. 


Examination of Living Cartilage.j—J. M. Prudden found the 
episternum of the frog, especially of Rana temporaria, an extremely 
good object in which to examine cartilage in the living animal. A 
moderately curarized frog should be taken, and an incision made in 
the skin from the lower jaw to the middle of the sternum, and then 
two cross cuts; the operator must turn back the edges of the skin, 
and divide the submaxillary muscle, thus exposed, near the middle, 
avoiding the large veins which pass inwards over the apex of the 
episternum. The latter lies at the bottom of the incision, being 
covered only by a somewhat loose connective tissue. If the delicate 
lamine of connective tissue between the episternum and hyoid bone 
are now cut through, and the head turned back at right angles to the 
body, the episternum is extruded from the wound, projects forwards, 

* Sci.-Gossip, 1881, p. 232 (1 fig. 


) 
+ Virchow’s Archiv, lxxv. pp. 185-98, Cf. Jahresber. Anat. u. Physiol., 
viii. pp. 11-12. 


nS 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 129 


and may be rendered accessible even to strong magnifying powers if 
placed on a glass block of suitable size. For prolonged observations 
the whole object may be attached to Thomas’s object-holder, with 
arrangement for irrigation, and may be kept in the natural fresh 
condition of life by irrigating with amniotic fluid or } per cent. salt 
solution. 

By this method Prudden was able, by irrigating with the latter 
fluid, to observe the cartilage cells in the episternum of the frog 
for many hours, in the living and fresh condition. Under these 
circumstances the intercellular substance appears homogeneous, 
the outline of the cell is very clear, and the cell-protoplasm has a 
finely granular appearance, with bright globules near the nucleus; 
the latter has a double contour, is penetrated internally by a number 
of fine lines, which meet at broader internodes. In this form of 
nucleus he could observe phenomena of movement, but could not 
determine that any effect was produced upon these movements by 
weak chemical reagents, by heat, or by electric currents. Under the 
action of 1 to 8 per cent. salt solution the cells shrink back from 
their walls, and are seen to be provided with numerous processes, 
which radiate to the walls of the cavities; vacuoles are also formed 
in the interior of the cells under these circumstances. When water 
is added to the solution, the cells resume their original appearance. 
Similar production of vacuoles under pathological conditions in cells, 
which have in like manner the power of reverting to the normal 
condition (Swetsky), the author believes to be explicable by an 
increase in the density of the liquid which the tissues contain. If 
the living episternum is irrigated with indifferent liquids and then 
replaced, the cells appear quite unaltered at the end of nine weeks. 

In an episternum which had been excised and placed in the lymph 
sac of a frog, the cells were found to be filled with yellow drops, 
soluble in ether, after five days, and the cell-nuclei stained with 
carmine. An identical degeneration of the cells, accompanied by 
susceptibility to staining with carmine, took place when the epister- 
num was exposed and replaced after its cells had been killed by 
chemical reagents or electric shocks. Carmine did not stain the 
nuclei at all in the living cartilage, neither after irrigation with 
2 per cent. salt solution, nor after subsequent dilution of this liquid 
with water, nor when the episternum had been restored to the body for 
some weeks; consequently the cells had not died. The author found 
that even very weak solutions of iodine, and also carbolic acid solutions 
of a greater strength than + per cent.—that is, solutions which are 
actually employed in the treatment of affections of the joints—caused 
the immediate death of the cells, so that when the tissue was subse- 
quently replaced the degenerative processes just mentioned set in. 
The author found that the cells of living cartilage collapsed under 
a temperature of 58° C., in detached pieces at that of 50° C., a lower 
temperature than that which Rollet found necessary. 


Statoblasts of Lophopus crystallinus as a Test for High-power 
Objectives.—Areolations of Isthmia nervosa.—Dr. John Anthony 
writes :—“ TI forward an object which I think will be found of value 

Ser. 2.—Vot. II. K 


130 SUMMARY OF CURRENT RESEARCHES RELATING TO 


as a test for high-power objectives, and which, not being a diatom or 
very diaphanous, needs rather the quality of ‘resolution’ than that of 
‘definition ’ to deal with it satisfactorily. I take it that a ‘test’ to 
be of use should be fairly easily obtainable; that the specimens 
should, from the nature of the structure, be uniform; and that to 
merit the name of a ‘test’ it should not be too easily made out, even 
by the best modern glasses. 

“T am sanguine enough to think that the statoblast of Lophopus 
erystallinus, which is easily procurable in any numbers, will be found 
to meet these conditions. The difficult part is the structure of the 
membrane, which seems to be stretched over the coarse hexagonal 
framework of the statoblast. I have seen it well, but it tried my 
fine =, of Tolles, and was most bright and clear with an excellent 
zy homogeneous-immersion objective, which Mr. Tolles has just sent 
tome. I found the more axial the illumination the better—obliquity 
was fatal. I used a cap on my condenser of ;3,, the diameter of 
condenser being 4, and it evidently aided the definition. 

“While on high-power testing, let me say that the hexagonal 
areolations seen in the apparent openings in Isthmia nervosa are 
valuable for trying the qualities of +, ,4,, and 1, or more. The areo- 
lations are not small, but so delicate as not to be seen at all by a poor 
object-glass, while the better the quality of objective the more clearly 
can they be made out, till they look like delicate network. I mention 
this because I find the existence of this delicate structure is not 
generally known; though I have used it for some years to try the 
quality of objectives.” 


Microscopical Structure of Malleable Metals.*—The following 
observations have been made by Mr. J. V. Elsden on the minute 
structure of metals which have been hammered into thin leaves. 
Notwithstanding the great opacity of metals, it is quite possible to 
procure, by chemical means, metallic leaves sufficiently thin to examine 
beneath the Microscope, by transmitted light. Silver leaf, for instance, 
when mounted upon a glass slip and immersed for a short time in 
a solution of potassium cyanide, perchloride of iron, or iron-alum, 
becomes reduced in thickness to any required extent. The structure 
of silver leaf may also be conveniently examined by converting it into 
a transparent salt by the action upon it of chlorine, iodine, or bromine. 
Similar suitable means may also be found for rendering more or less 
transparent most of the other metals which can be obtained in leaf. 

An examination of such metallic sections will show two principal 
types of structure, one being essentially granular, and the other 
fibrous. 

The granular metals, of which tin may be taken as an example, 
present the appearance of exceedingly minute grains, each one being 
perfectly isolated from its neighbours by still smaller interspaces. 
The cohesion of such leaves is very small. 

The fibrous metals, on the other hand, such as silver and gold, 
have a very marked structure. Silver, especially, has the appearance 


* ‘Nature, xxiii. (1881) p. 391. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. apt 


of a mass of fine, elongated fibres, which are matted and interlaced in 
a manner which very much-resembles hair. In gold, this fibrous 
structure, although present, is far less marked. ‘The influence of 
extreme pressure upon gold and silver seems to be, therefore, to 
develope a definite internal structure. Gold and silver, in fact, appear 
to behave in some respects like plastic bodies. When forced to 
spread out in the direction of least resistance their molecules do not 
move uniformly, but neighbouring molecules, having different velo- 
cities, glide over one another, causing a pronounced arrangement of 
particles in straight lines. 

This development of a fibrous structure, by means of pressure, in 
a homogeneous substance like silver, is an interesting lesson in expe- 
rimental geology, which may serve to illustrate the probable origin 
of the fibrous structure of the comparatively homogeneous limestones 
of the Pyrenees, Scotland, and the Tyrol. 


Sections of Fossil Coniferous Woods.—Voigt and Hochgesang of 
Gottingen have issued (price 65 marks) a collection of seventy micro- 
scopic slides of coniferous woods, fossil and recent, prepared by 
Professor Goppert. The present collection is a first instalment only, - 
and is devoted to the Araucarieze. Where possible, each species is 
represented by three sections, one transverse, the second central or 
radial, and the third cortical or tangential. Sections of recent woods 
are placed side by side with those of the most nearly allied fossil 
woods; as sections of an Araucaria (A. Cumninghami) and of a 
Dammara (D. australis) by the side of the fossil Araucarites. The 
preparations are arranged in a polished mahogany box with ledges, 
and have been made on slides of white glass 50 x 33 mm., and 
1'5 mm. thick, with polished edges, under square cover-glasses of 
18 mm. length and breadth, in Canada balsam. Only those of the 
recent Araucariez are under round cover-glasses of 20 mm. diam. in 
glycerine. The sections have been made with the greatest care and 
skill. Instead of the ordinary length of about 4 mm., these are 
of double or treble that length, so as to render possible a more com- 
plete examination. Special care has been taken to furnish sections 
which illustrate the nature of the process of petrifaction. 


Aeration of Laboratory Marine Aquaria.*—The plan shown in 
Fig. 27 is recommended by M. Kunckel d’Herculais for aerating 
a salt-water aquarium by means of a fall of fresh water. 

The figure shows two aquaria, A being fresh-water and B salt- 
water. In the first case the process is of course very simple, the 
water from the pipe C passing down the tube H, air being obtained 
through the tube F and pipe D which communicates with the open 
air so as to prevent air being abstracted from the confined laboratory. 

In the case of the salt-water aquarium B, the fresh-water passes 
from the pipe C down the tube G into the bottle H, with three 
openings, which holds about two litres, air being obtained as before 
from the open air through D and the tube shown on the right. A 


* See ‘Manuel de Zootomie,’ par A, Mojsisovics, traduit par J. L. de Lanessan 
(8vo, Paris, 1881), pp. 61-6 (1 fig.). 
Kee 


132 SUMMARY OF CURRENT RESEARCHES, ETC. 


third tube I conducts the air from the bottle to the aquarium, while 
the water escapes from the bottle through the tap at the bottom. All 
that is necessary is to regulate the flow into and out of the bottle in 
such a way that the water shall be at a constant level. When this 
has once been experimentally ascertained the aquarium may be left 


Fic. 27. 

TTA ATTN ATTA TT AAT ATA TTT 
CH | (A ll | | A AUS INIA I MAA I lus 
| ETT 
| eC th AND A 
| ER 

| | | (| 
| | = z = ie = 
= IN Emi= 
| SS =a + = 
ULQUUUUNULLUNUNUAVA ALUN Il 
I 
RUFFLE 


without fear day and night. If the bottle were allowed to get empty 
the aeration would of course stop, while if it were filled the fresh 
water would pass into the aquarium. In order to supply the loss 
from evaporation a little fresh water should be added from time to 
time, which will prevent the necessity for renewing with salt water. 

The apparatus will pass 223 litres of air per hour through an 
aquarium of 90 litres at an expenditure of water of 36 litres. In 
this case the exit tube for the air, 5 mm. in diameter, is plunged 11 cm. 
into the aquarium. If the tube is plunged lower, say 36 cm., the 
pressure of the water which obstructs the exit of the air is greater, 
and 45 litres of water would be expended in passing 16 litres of air, 
i.e. 9 litres of water more, and 63 litres of air less. In the author’s 
opinion, apart from the increase in the expenditure of water, it is un- 
desirable that the air tube should go to the bottom of the aquarium, as 
the disturbance to the water which is thus caused is unfavourable to 
the development of delicate animals. 

To ensure that the air-bubbles shall be small, the air tube is 


terminated by a small sphere with half-a-dozen very small orifices at. 


its equator, and enveloped with two or three thicknesses of muslin. 


oun Te er 


@ 3133 4) 


PROCEEDINGS OF THE SOCIETY. 


Meerrine or 147TH Decemser, 1881, ar Kine’s Cottecer, Stranp, W.C., 
Tue Presipent (Proressor P. Martin Duncan, F.R.S.) in THE 
Cuatr. 


The Minutes of the meeting of 9th November last were read and 
confirmed, and were signed by the President. 


The List of Donations (exclusive of exchanges and reprints) 
received since the last meeting was submitted, and the thanks of the 
Society given to the donor. 


From 
Micrographic Dictionary. 4thed. Parts4-6. .. .. .. Mr. Van Voorst. 


Mr. Crisp exhibited Parkes’ Drawing-room Microscope with 
magnetic stage, and two bottles from Professor H. Van Heurck, of 
Antwerp, containing new fluids for use with homogeneous-immersion 
lenses ; one (‘‘ liquide homogéne & la tacamaque”) with a refractive 
index of 1:510, and a dispersive power of ‘0072, and the other (“a 
Voliban) of the same index, but with a dispersive power of :0077. 


Mr. John Mayall, jun., exhibited Mr. Deby’s method of turning 
the correction-collar of objectives, the chief peculiarity of which was, 
that the collar was worked by a tangent screw (with a long arm) 
acting upon a worm-wheel, instead of by the ordinary collar-adjust- 
ment, which Mr. Deby had found to be inconvenient (see p. 107). As 
at present made, it would not go into an ordinary box, but (as had 
been pointed out by Mr. Beck) the screw pinion might be con- 
siderably shortened, so as to admit of its being put in a box in the 
usual way. 

Mr. Beck said that it must be borne in mind that in adjusting an 
object-glass it was often desirable to get a sudden adjustment, which 
could not be very well done with this form. 


Mr. T. Charters White described, by means of black-board 
drawings, a new form of growing or circulation slide which he had 
recently devised, and exhibited the slide in action under a Microscope 

see p. 19). 

Mr. on Smith said he had been trying himself to work out 
some better form of growing-slide than those in common use, but his 
attempts had hitherto proved abortive. He was, however, very much 
pleased with the one now shown by Mr. White, the great advantage 
of which was its extreme simplicity, and its capability of keeping 
objects alive for any length of time. 

The President thought that its only disadvantage would be that 
when carefully examining one particular individual, others might be 


134 PROCEEDINGS OF THE SOCIETY. 


introduced into the cell by the flowing water. With some kinds of 
organisms there would, of course, be no such danger, but it would 
hardly be safe with an Ameba, for instance. He had himself found, 
when studying the life-history of minute species, that it answered 
very well to make a small cell of ordinary thin glass, and by 
surrounding the whole with blotting-paper, kept constantly wet, he 
had been able to retain three or four monads of large size under con- 
stant observation for several weeks. A similar arrangement to that 
adopted by Mr. White had been used on the human body as a means 
of applying evaporating lotions. 


Mr. J. W. Stephenson said he had brought for exhibition some 
scales of insects (Machilis maritimus and Tomocertus | Podura] plumbea), 
mounted in phosphorus, and shown under a ;},-inch objective with 
very oblique light and the binocular. They demonstrated that it was 
possible even with such a high power to get with the binocular a 
distinctly stereoscopic effect, and that when so seen a much more 
perfect idea of the structure of the scale could be obtained than was 
possible under the monocular. Although the structure of the scales 
of Machilis maritimus and Tomocertus plumbea is probably the same, 
they cannot be said to be “corrugated” in either case. In Machilis 
the appearance of the upper side is that of longitudinal semi-cylin- 
drical grooves, which had been likened by a medical gentleman to a 
pill machine ; whilst the latter, probably from being so much smaller, 
appears to have rectangular grooves, similar to those in a curry-comb, 
the back being in each case supported by slender transverse bars, 
which are approximately from one-third to one-half the distance 
apart of the longitudinal divisions. 

Mr. Beck said that as to the Podura scale shown by Mr. Stephen- 
son, what he described with respect to the structure of the scales was 
entirely opposed to what they had been shown to be. In such 
matters where high powers and oblique light were used, he thought 
it was very doubtful if they ought to believe what they saw, as they 
might so very easily be deceived by appearances. So far as he knew, 
no one had hitherto brought forward anything which would refute 
what he had shown some years ago, when he put moisture on one side 
of a scale, and found that it dried off quite flat, whilst if he put some 
on the other side, it ran up and down as if in corrugations. His 
brother also did the same kind of thing with a Lepisma scale and 
Canada balsam. Moisture, as they knew, would get into slides which 
were mounted dry, and the same appearances were presented there. 
Having kept the insects, and being able to tell which was the upper, 
and which the under side of the scale, and being also able to show 
these corrugations in a mechanical way, he could only say that even 
if the effect could be seen as described by Mr. Stephenson, he should 
not, he was afraid, be convinced, for he knew very well that in most 
cases, by reversing the shadows, they could reverse the appearances. 
If they wanted to determine the real structure with high powers, they 
must argue from analogy rather than from what theysaw. They had 
compound substances to deal with, and effects were produced which 


eis. 


PROCEEDINGS OF THE SOCIETY. 135 


had to be studied and analyzed and examined very carefully. Unless, 
therefore, any one could show upon the upper side what he had shown 
mechanically on the under side, he considered that the appearances 
obtained by simple vision were deceptive. 

Mr. Stewart said he understood that some time since a microtome 
was made, so delicate in its adjustment as to be able to cut sections of 
a valve of a diatom. Could not this be made available for making 
sections of the scale which would show the configuration of it as 
conclusively as if done in the mechanical way ? 

Mr. Crisp said that the existence of such a microtome (cutting 
150 consecutive sections of the brain of a cockroach) had been 
reported, and he had endeavoured to obtain it, but hitherto in vain. 
So far as he knew also, no results obtained from any actual sections 
had been published, other than those which appeared in the ‘ Archiv 
f. Mikr. Anat.’ in 1870. The further and more recent series pro- 
mised by Dr. L. Flogel * had not been heard of. 

Mr. Stephenson said that notwithstanding Mr. Beck’s remarks, 
he could not but feel clear as to its being the upper side of the scale 
on which these grooves were, for the pedicel or “quill” of the 
“ feather,” which is necessarily on the under side of the scale, was 
bent down from the plane of the scale, and the markings were clearly 
on the opposite side to that. 


Dr. John Anthony’s note was read by Mr. Stewart, suggesting 
the statoblasts of Lophopus crystallinus as a test for high powers (see 
p. 129). The difficult part was stated to be the structure of the mem- 
brane. The portions of the statoblasts referred to were drawn on 
the board and further explained by Mr. Stewart. 


Mr. Guimaraens called attention to what appeared to be a male 
specimen of the Hchinorhynchus of Lota vulgaris with ova in the 
interior, described as “ dedans par hasard.” 


Mr. A. D. Michael read a paper, “Further Notes on British 
Oribatide ” (see p. 1), which Professor Huxley and others state to be 
wholly viviparous. He found, however, that they are chiefly ovi- 
parous, as stated by Nicolet and others, and that the young are 
brought to maturity in, at least, four different modes :—1st. The egg is 
deposited in a slightly advanced stage, as in insects. 2nd. Deposited 
with the larva almost fully formed. 3rd. The female is occasionally 
viviparous (in these modes only one egg is usually ripe at a time). 
4th. Several eggs are matured at once, but not deposited. The mother 
dies, the contents of her body, except the eggs, dry up, and her 
chitinous exterior skeleton forms a protection throughout the winter 
to the eggs. The occurrence of a deutovum stage in the egg is 
recorded, i.e. the egg has a hard shell which splits into two halves 
as the contents increase in volume, the lining membrane showing 
between, and gradually becoming the true exterior envelope of the 


* See this Journal, i. (1881) p. 509. 


136 PROCEEDINGS OF THE SOCIETY. 


egg. Several new and interesting species were described and figured, 
and exhibited under Microscopes. 

The President said he was very glad that Mr. Michael did not 
form a new species from a single specimen. ‘The history of the 
death of the parent insect before the escape of the ova was, he 
thought, very anomalous in nature; indeed, he did not remember 
anything at all like it. Many of the Lepidoptera died very soon after 
the eggs were laid, but he knew of no case in which this remarkable 
circumstance had been observed. 

Mr. Stewart did not remember any in which the eggs were retained 
in the body of the dead mother, but in the case of the Coccus there 
was something, perhaps, a little like it, the mother dying immediately 
after the deposition of the eggs, and forming a sort of roof over 
them with her.dead body, which served to protect them during the 
winter. 


Mr. J. W. Stephenson exhibited Pleurosigma formosum mounted 
in a solution of biniodide of mercury and iodide of potassium, a 
mounting fluid which, with the exception of solution of phosphorus, 
had a higher refractive index than anything known to him. It had 
been used by Mr. Browning for prisms, and had an index of 1-68. 
The index of bisulphide of carbon was 1°624, of monobromide of 
naphthaline, 1-658, and of sulphur, 1°662, so that the biniodide of 
mercury was *056 higher than bisulphide of carbon. Mr. Browning 
found that the best means of sealing it was by using white wax. He 
had brought some of it to the meeting as a sample. Being an aqueous 
fluid appeared to be a great advantage, and it could be used of any 
strength from 1°33 to 1°68. 

The President said he had had his eyes opened to the value of 
this solution as a highly refractive medium, but had been disappointed 
by being told that it was only useful for purposes of spectrum analysis, 
in consequence of the great effect which it had on the red rays. 

Mr. Stephenson did not know how far its great dispersive power 
would be prejudicial, but he had tried it for mounting, and found that 
it did very well for diatoms. 


Mr. Symons read a paper on “A Hot or Cold Stage for the 
Microscope ” (see p. 21), the details of which were drawn upon the 
board and the apparatus itself exhibited. 

The President inquired if Mr. Symons had used this stage for 
observing the motion of the white blood-corpuscles. He also 
suggested that the brass would be better if it came rather more flush 
with the plate. 

Mr. Symons had not examined corpuscles with the stage, having 
hitherto only applied it to ascertaining the melting-points of various 
substances. He thought there would be no difficulty in using high 
powers with it, as the objective could be brought into actual contact 
with the glass if desired, the only thing between the plate and the 
objective being the thin glass, 


PROCEEDINGS OF THE SOCIETY. 137 


The following Instruments, Objects, &c., were exhibited :— 

Mr. Crisp :—Parkes’s “ Drawing-room” Microscope with magnetic 
stage. 

Mr. Deby:—New method of moving the correction-collar of 
objectives (see p. 107). 

Mr. Guimaraens :—Echinorhynchus of Lota vulgaris. 

Mr. Michael :—Cepheus ocellatus n. sp. Nymph—showing the eye- 
like appearance of the stigmata and stigmatic organs. Dameus 
monilipes n. sp.—showing the tibiz of the first pair of legs. Leiosoma 
palmacinctum—internymphal ecdysis showing arrangement of the 
palmate hairs on new skin forming within present one. Notaspis 
licnophorus n. sp.—showing the stigmatic organs. 

Mr. Stephenson:—Scales of Machilis maritimus and Tomocertus 
(Podura) plumbea, mounted in phosphorus under ;;-inch objective 
- and binocular (see p. 184). 

Mr. T. C. White:—New form of Growing or Circulation slide 
(see p. 19). 


New Fellows.—The following were elected Ordinary Fellows :— 
Messrs. William Blackburn, Walter H. Coffin, F.L.S., F.C.S., the 
Hon. William Nassau Jocelyn, and Theodore Wright. 


CoNVERSAZIONE. 


The first Conversazione of the Session was held on the 7th 
December last in the Libraries of King’s College. 
The following were the objects, &c., exhibited :— 
Mr. C. Baker: 
Stephenson’s Erecting Binocular Microscope for Laboratory use. 
Homogeneous-immersion and Glycerine-immersion Objectives by 
Gundlach and Zeiss. 
Abbe’s Apertometer and Immersion Illuminator. 
Dissecting Microscope by Zeiss. 
Dr. Beale: 
Muscular fibres of the bladder of Hyla. 
Nerve-fibres of ditto. 
Capillaries and nerve-fibres of the palate of the common frog. 
Messrs. R. and J. Beck: 
Pleurosigma angulatum with their new 4 object-glass. 
Mr. W. A. Bevington: 
Isthmia nervosa in situ. 


Mr. W. G. Cocks: 
Ophrydium and a remarkably large form of Epistylis. 
Mr. J. E. Creese: 
Radiolarian ooze from the ‘Challenger’ Expedition (2600 
fathoms). 
Mr. Crisp: 
Colouring matter from willow-tree Aphides (Lachnus viminalis), 
polarized, showing the characteristics of Salicine. Prepared 
by Mr. C. J. Muller in illustration of his paper (ante, p. 39). 


138 PROCEEDINGS OF THE SOCIETY. 


Mr. T. Curties: 
Schizonema Grevillet in situ. 
Mr. L. Dreyfus: 
Spirorbis nautiloides from a shell. 
Professor P. M. Duncan : 
Spheridia from a Spatangoid. 
Cliona from a coral. 
Mr. F. Enock: 
Battledore fly (Mymar pulchellus). 
Eyes of spider (Salticus tardigradus). 
Mr. F. Fitch: 
Dissection of blow-fly, showing abnormal condition of sucking 
stomach. 
Mr. C. J. Fox: 
Various diffraction effects produced by rectilinear and circular 
gratings. 
Mr. D. W. Greenhough: 
Crystals of asparagine. 
Mr. J. F. Gibson : 
Collection of seeds of British flowering plants. 
Mr. W. H. Gilburt: 
Section of Sporangium of Equisetum limosum, showing division of 
nuclei in spore-mother-cells. 
Dr. Heneage Gibbs: 
Bacteria in kidney. 
Mr. J. W. Groves: 
Lymphatics in web of frog’s foot injected with silver nitrate. 
Transverse section of stem of Smilax officinalis stained with 
magenta, iodine green, and Nicholson’s blue. 
Mr. A. de Souza Guimaraens : 
Diplozoon paradoxum from carp. 
Mr. H. F. Hailes: 
Dactylopora and other Foraminifera from the Paris basin. 
Mr. J. Hood: 
Coccochloris cystifera and some Rotifers. 
Messrs. Hopkin and Williams: 
A large specimen of bichromate of potash crystals (14 lbs.). 
Mr. J. Hunter: 
Upper and lower jaw of cat, &c., with Polariscope. 
Mr. J. E. Ingpen: 
Illustrations of Professor Abbe’s diffraction experiments, 
Mr. W. Joshua: 
Desmids of many species from North Wales and other places. 
Cidogonium Wolleanum Wittr. 8 insigne Nordst. Stromsberg, 
Sweden. Ex Herb. Dr. Otto Nordstedt. 
C. Wolleanum Wittr. in Rab. Alg. Eur. No. 2547. Exs. Wittr. 
& Nordst. Alg. aq. dulce. exsic. fase. 3, No. 107. This 
species has its place between C&. Borisianum (Le Cl.) Wittr. 
and CE. concatenatum (Hass) Wittr., but is well distinguished 
from both; among other things through the fact that the effect 


PROCEEDINGS OF THE SOCIETY. 13Y 


of the fecundation extends not only to the oosphere but also to 
the wall of the oogonium. This wall increases in thickness 
after the fecundation, receiving at the same time longitudinal 
costz on its inner side. 
Mr. A. D. Michael : 
A new species of Hypopus. 
Hremeus cymba, one of the rarest of the British Oribatide. ~ 
Dr. Matthews: 
Corticium abyssi, and other sponges. 
Dr. Millar : 
Bacteria which convert nitrites into nitrates. 
Mr. Millett : 
A species of Acetabularia from the Lagunes near Cette. 
Mr. E. M. Nelson: 

Nobert’s 19th band (112,595 lines to the inch), with Powell 
and Lealand’s oil-immersion +, (N.A. 1-428), and their vertical 
illuminator (x 1000 diameters). 

- Pleurosigma formosum, in balsam. Showing the sieve-like struc- 
ture, with Zeiss’s DD (2) objective (N.A. °81), and direct 
light from Powell and Lealand’s achromatic condenser (x 950 
diameters). 

Micrococcus in balsam, showing flagellum (length ;,),, of an 
inch), with Powell and Lealand’s oil-immersion ,, (N.A. 
1-237), and direct light with achromatic condenser (x 1250 
diameters). 

Lieut.-Colonel O’ Hara : 

Crystals in poison of Bungarus ceruleus, an Indian snake. 

New genus of Homoptera (Colydiide) from ant’s nest in India. 
Messrs. Powell and Lealand : 

Amphipleura pellucida in phosphorus, with an oil-immersion 1 
(N.A. 1:47). 

Mr. B. W. Priest: 

Diastopora obelia. 

Mr. §. O. Ridley : ; 

Vertical sections of Halichondria panicea Johnston (Crumb-of- 
bread Sponge), prepared by the method adopted by Professor 
F. E. Schulze for Huplectella aspergillum (Trans. R. Soc. Edin- 
burgh, xxix., ii., p. 661). 

Mr, J. Smith: 
Pleurosigma formosum and P. angulatum, with +1, immersion- 
objective. 
Mr. George Smith: 
Dolerite from Liassic strata, Portrush, Co. Antrim, &e. 
Mr. J. W. Stephenson : 
Surirella gemma in phosphorus, with catoptric illuminator and 
Zeiss’ homogeneous 4. 
Mr. C. Stewart: 
Water spider imbedded in the nacreous layer of an Anodon. 
Young sole. : 


140 PROCEEDINGS OF THE SOCIETY. 


Mr. W. H. Symons : 

Fatty acids melting and congealing on new hot and cold stage. 
Mr. C. Tyler: 

Hyalonema mirabilis, &c. 
Mr. H. J. Waddington : 

Pseudomorphs. Copper. Copper formate reduced by heat. The 
resulting copper retaining the forms of the original crystals, 
and analytic crystals of magnesium platino-cyanide polarized 
with one prism. 

Mr. F. H. Ward: 
Section of stem of Nymphcea alba, Rosa canina, Eucalyptus globulus, 
&c., double stained. 
Mr. C. White: 
Corethra plumicornis. 
Pellets of Melicerta showing them to be apparently hollow. 
Messrs. Watson & Sons: 

Pleurosigma formosum with large angle }, and P. angulatum with 

1 objective and Crossley’s swinging tail-piece Microscope. 


Meetine or lltu Janvary, 1882, ar Krine’s Cottuce, Stranp, W.C. 
Tur Presipent (Prov. P. Martin Duncay, F.R.S.) In THE CHarR. 


The Minutes of the meeting of 14th December last were read 
and confirmed, and were signed by the President. 


The List of Donations (exclusive of exchanges and reprints) 
received since the last meeting was submitted, and the thanks of the 
Society given to the donors. 


From 

Davies, G. E.—Practical Microscopy, viii. and 335 pp., 

1 pl. and 257 figs. (8vo, London, 1882).. .. .._.. The Author. 
Retzius, G—Das Gehororgan der Wirbelthiere. I. Das 

Gehérorgan der Fische und Amphibien. 222 pp., 35 pls. 

(Fol. Stockholm, 1881) ta ey EPR ee ee ne er Ditto. 
Micrographic Dictionary, 4th ed., Part 7 ve ce ee) ge IM Vann Voonere 
Eupodiscus argus mounted in gum-juniper.. = «. = «. 30s.) Mr. F, Kitton. 


The President called the special attention of the meeting to Prof. 
Retzius’ work as one of exceptional excellence, and constituting a very 
handsome donation. 


Mr. Badcock and Mr. Butler were appointed Auditors to audit 
the Treasurer’s accounts. 


The List of Fellows to be recommended to the Society for elec-. 
tion as Members of the Council at the ensuing annual meeting in 
February, was read in accordance with the 44th Bye-law. 


The President gave notice that at the next meeting an altera- 
tion would be proposed in the Bye-law relating to the payment of 


PROCEEDINGS OF THE SOCIETY. 141 


subscriptions, so that Fellows elected in any month after February 
would only be called upon to pay a proportionate part of the sub- 
scription. 


Mr. Crisp exhibited Beck’s Miner’s Binocular Microscope, intended 
for rough use in the field, and a photograph by Mr. Jennings of -001 
erains of arsenic x 400. 


Mr. Beck exhibited and described a new achromatic condenser 
for dry and immersion objectives, with five different front lenses set 
in a drum capable of being rotated consecutively over the back 
combination, and giving apertures from 7° in air to 110° in glass 
(1°25 N.A.). Mr. Beck stated that the mode of setting the front 
lenses avoided the inconvenience of haying the immersion medium 
drawn away by capillary attraction, as would be the case if the 
lenses were mounted on a flat surface, as in previous forms. 


Mr. Stewart exhibited and described a specimen of Gregarinide, 
from the vesicule seminales of the earth-worm, and explained their 
mode of growth and development, calling attention to the spines 
frequently observed upon them, and which he inclined to believe were 
bond fide cuticular appendages. 


Mr. J. W. Stephenson read a paper “On Mounting Objects in 
Phosphorus, and in a solution of biniodide of mercury and iodide 
of potassium,” in which he explained in detail the methods which 
he had found the most successful for the purpose. 

Mr. Stewart thought that the biniodide would prove of very 
great value as a mounting medium, on account of another of its 
qualities not alluded to in the paper, namely, its chemical properties 
as an antiseptic. He believed he was correct in saying that it 
possessed the valuable power of preserving the colours of many 
delicate vegetable tissues, and that chlorophyll was not changed by it ; 
blues would be found to fade a little, but red was kept well, and he 
thought that the fluid promised to be of great value in mounting such 
organisms as desmids, the beauty of which was so greatly increased 
by seeing them in their natural green colour. 

The President said it occurred to him that these fluids might 
be also of great use in enabling any one to see other difficult objects, 
such, for instance, as coccoliths; they were very difficult to see in 
the ordinary way, and he would suggest to Mr. Stephenson to try 
whether they might not be made out more easily by means of such 
media as he had described. 


Mr. Crisp read a paper ‘“‘ On the conditions for Utilizing the Full 
Aperture of Wide-angled Immersion Objectives.” 


142 PROCEEDINGS OF THE SOCIETY. 


Mr. Forrest's Compressorium (received 31st October last and 
accidentally mislaid) was exhibited and described. It is designed 
with a view to cheapness, and differs from the Wenham com- 
pressorium in the action of the spring and screw being reversed, so 
that instead of the spring putting on the pressure and the screw 
releasing it, the screw puts the pressure on and the spring releases it. 
It is claimed that this in practice will be found an advantage as it 
enables the observer to feel what pressure is put on. 


Mr. Crisp referred to the erroneous statements that had been 
made as to the supposed advantages of Mauler’s blue glass slides in 
“shortening the wave-lengths and so giving increased resolving 
power.” The fact was that they were intended to be used with 
objectives affected with chromatic aberration, the performance of 
which was thereby greatly improved. A letter from M. Mauler was 
read to the meeting, in which he mentioned that the blue mounts 
would be found useful in the case of delicate histological preparations. 
They also agreeably modified the ordinary yellow light of gas and oil 
lamps. 


Mr. Kitton’s note on the use of gum-juniper for mounting 
diatoms was read. It has an index intermediate between water and 
balsam, and is soluble in methylated spirit. Preparations may be at 
once transferred from the spirit to the dissolved gum. 


Dr. Anthony’s paper “On the Threads of Spiders’ Webs” was 
read by Mr. Stewart, enlarged copies of the illustrations being drawn 
upon the black-board. 

The President said that Dr. Anthony had certainly exercised 
great ingenuity in his methods of procedure. He believed that the 
nature of the thread depended upon the spinnerets which were 
used. 

Mr. James Smith said that, in watching the process of an attack 
by a spider upon a fly, he observed that, at the commencement, only 
two or three spinnerets were used to spin the web round the fly. The 
first portion of the web was like a quantity of floss silk, and then, as 
the web converged towards the fly it became more like a gut-line. 
After a while the fly began to struggle, and then the spider used some 
more web, and finally used all-five spinnerets. He thought, from 
what he had seen, that the quantity or quality of the web depended 
upon what the spider wanted to use it for, and, according to this, he 
used more or less of the spinnerets. ; 

The President inquired whether Dr. Anthony should not have 
used the word “she” in speaking of the spider. Was it not the 
female spider which spun the webs ? 

Mr. Stewart said he had often seen the male spider in the middle 
of a web waiting for his prey, and always thought it was his own web, 
for he certainly would not venture into the web of a female, knowing very 


Sat * 


PROCEEDINGS OF THE SOCIETY. 143 


well what his fate would be. He believed that the explanation given 
was quite correct, and that not only were the spinnerets of varied 
form, but the glands inside them were different in structure so as 
to be able to produce different kinds of threads. The cross threads, it 
might be observed, contained an axis of comparatively hard, dry thread, 
which was exceedingly elastic, and the outside portion was glutinous, 
like birdlime, and remained so for years. If the thread was stretched this 
would be seen to be the case; the gelatinous portion would break up 
into beads. 

Mr. Beck said that it was quite easy to examine the different 
kinds of webs which were spun by a spider, and if they allowed the 
spider to run out one of the glutinous threads, they could observe the 
formation of the web and the globules. He had had frequently to 
_use spiders’ webs for the cross-lines of transit instruments, for 
instance, and the kind used were not at all adhesive. Any one who 
had watched a spider encasing his prey would have noticed how 
entirely the web seemed to be under command, and that there appeared 
to be a remarkable power of changing the character of the web at will. 
The spinning-organs were very highly developed and would form a 
very good subject for a monograph. 

Mr. Crisp referred to the researches of the Rev. H.C. McCook on 
spiders’ webs.* 

Dr. Matthews inquired how it was that the spider dropped or 
divided his web without using his jaws, and how it was that he climbed 
up his web, if it was composed of glutinous threads ? 

Mr. Beck said that a spider did not always use glutinous threads. 
The radial lines of the web were not glutinous; neither were those 
which were used to tie the web fast to neighbouring objects; but only 
the transverse lines. 

Mr. Michael said that any one who watched a spider, would see 
that he took great care not to put his foot on the transverse lines of 
his web; but that in running across it he always walked on the radial 
lines only. 

Mr. Crisp said that in a letter to Mr. Mayall, Dr. Anthony had 
anticipated Dr. Matthews’ query as to the division of the web, and 
proposed to show in a further communication on the spinnerets that 
the spider did not use his jaws for the purpose, but that there was a 
special apparatus at the end of the spinnerets. The diagram accom- 
panying the letter illustrating this apparatus was enlarged upon the 
black-board by Mr. Stewart. 


Mr. Badcock said he had brought some specimens of Lophopus 
erystallinus to show what might be found in the depth of winter, A 
pond in Epping Forest a few days ago had what looked like a mass 
of fungi in the middle of it,and on examination it turned out to be an 
immense quantity of Polyzoa. He thought that naturalists often 
failed to find things because they did not look for them in the winter. 


* See this Journal, ii. (1879) p. 559, and Proce. Acad. Nat. Sci. Phila. 1881. 


144 PROCEEDINGS OF THE SOCIETY. 


The pond in question contained nothing of any consequence in the 


summer. 
Mr. Stewart said that the specimen exhibited by Mr. Badcock was 


the finest he had ever seen. . 


The following Instruments, Objects, &c., were exhibited :— 

Mr. Badcock :—Lophopus crystallinus. 

Messrs. Beck :—New Condenser (see p. 141). 

Mr. Crisp :—(1) Beck’s Miner’s Binocular Microscope. (2) Photo- 
graph by Mr. Jennings of +001 grain of arsenic x 400. (3) Mauler’s 
blue glass slides. 

Mr. Forrest :—New Compressorium. 

Dr. Gibbes:—(1) Bacillus anthracis in lung. (2) Section of 
tongue treble stained and injected. 

Mr. Kitton :—Eupodiscus argus mounted in gum-juniper. 

Mr. Stephenson :—Specimens illustrating his paper on mounting. 

Mr. Stewart :—Gregarinide from vesicule seminales of the earth- 


worm. 


New Fellows.—The following were elected Ordinary Fellows :— 
Messrs. W. J. Abel, Herbert C. Chadwick, Walter H. Mead, and 
James Warnock. 


— 


ee 


The Journal is issued on the second Wednesday of 
February, April, June, August, October, and December. 


: Sizer Ser 8 
Ser, II. ‘ APRIL. 1882 To Non-Fellows, HG 
Vol. II. Part 2. } : { Price 4s. 


= | 


= JOURNAL 


ROYAL ee 
 MICROSCOPICAL SOCIETY; 


CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, 


-‘ AND A SUMMARY OF CURRENT RESEARCHES RELATING TO 


ZOOLOGY AND BOTANY 
(principally Invertebrata and Cryptogamia), 


MICROSCOPY, &c- 


Edited by 


FRANK CRISP, LL.B., B.A., 
One of the Secretaries of the Society 
ae a Vice-President and Treasurer of the Linnean Society of London. ; 


WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND 


x A. W. BENNETT, M.A., B.Sc., -E, JEFFREY BELL, M.A,, 
~ Lecturer on arany at St. T, iim Ss Hospital, Professor of C omparative Anatomy in King’s College, 


{ 
| 
8. 0. PABEEN, MLA, of the British Museum, aND JOHN MAYALL, Jon., 
/ 
. 
| 


FELLOWS OF THE SOCIETY, 


“WILLIAMS & NORGATE, = 
LONDON AND EDINBURGH. ) 


y 
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WM. CLOWES AND SONS, LIMITED,] s [STAMFORD STREET AND CHARING CROSS. 


Cra ioe 


JOURNAL 


OF THE 


ROYAL MICROSCOPICAL SOCIETY. — 
Ser. 2.-Vot. Il. PART-2. .S 
(APRIL, 1882.) . 


CONTENTS. 


_—o;00—— : ; : 
TRANSACTIONS OF THE SocraTy— eee 
IV.—Tue Presrpent’s Appress. By Prof. P. Martin Duncan, M.B. 

Lond ERs M026 ee. as saad 

V.—On Movntine Ossects In PHospHorvs, AND IN A SoLuTion oF. 

Braropipr or Mercury AnD Iopipr or Porasstum. By John 

Ware Stephenson, Vice-President R.M.S., P.R.AS. 3. 5, 

VL—Ow tae Tareaps or Sprpers’ Wess. By John Anthony, MD. 
E.R.MS., &e. oe ee ae ee ee ey we oe CY ed 7 f 


Summary or Current RaseaRcHEs RELATING TO ZooLoGy AND 
Borany (PRINCIPALLY INVERTEBRATA AND CryProgamia), Mioro- — 
soory, &c., INCLUDING ORIGINAL COMMUNICATIONS FROM FELLows. a 
AMD ORHERS 2505 9 C0 rls oe oe ps me ee 


: - ZooLoay. — 


Germinal Layers and Early Development of the Mole .. +1 v1 +e ne 
Development of Amphioxus a ae Che oes anes ; 
Fossil Organisms in Meteorites .. +. ++ 
Red Pigment of Invertebrates (Tetronerythrine) +. «+ + ; 
Maturation, Fecundation and Segmentation of Limax campestris. +. + 
Kidney of Chiton Be ie eee cera LUNGS ob ee 
Morphology of Neomenta «1 5 ose ae ee ae te 
Organization and Development of the Ascidians .. ++ + 


ee oe oe o* can ;' 
oe ee of oe (aie 


of 


. oo ee oe 


-* Pe ae 


“ Challenger” Ascidians (Culeolus) Seen 
Embryonic Membranes of the Sulpide ~.. +. + see 
Modifications of the Avicularia in Bryozoa «+ ++ ++ ee ow 
Blight of Insects 2. 050 See ee ae a oe ae 
Nucleus of the Salivary Cells of the Larvx of Chironomus ..  .._ 
ee) Structure of the Dermaleichide .. 1. 2 ee ey ne pee 
- New and rare French Crustacea (Fig. 28) ++ ee ee ee 
- New British Cladocera from Grasmere Lake... .. ++ +4 
The Entoniscida 00 3 ant toe oe ae ee Oo 
Phe Bopyridse 2255 6B. hey eno be 5 AR pk oe a ae ae ; 
- Anatomy and Histology of Scoloplos armiger + s+ we ew 
Parasitic Eunicid .. ee ee on : 
~~ Development of Anguillula stercoralis, +. 4 tem we we es 
_Cercuria with Caudal Sete 0 ee ee te ae ne 
“New Type of Turbellaria 2.00 se weoc ee ee eee ee 
- Systematic Position of Balanoglossus 5) «+s ve 4 
| Nervous System of Platyhelminthes .. +1 +5 ++ ee ae 
Structure of Gunda seqmentata, and the Relationships of the Plat 
with the Coelenterata and Hirudinea © ss se oe. we 
Nervous System of the Ophiuroidea .. 1. ve ee ty ve 
American. Comatulee 92) 24. se oak ne) nes de a ae 
Characters of Stinging-cells of Coelenterata 1. +1 i) +s wn 


(ey: 


Summary or Current Resmancuss, &e.—continued. 


Development of the Celenterata..  .. +s +» oe ee 
Nervous System of Hydroid Polyps ..- .. «+ ss oes 
Remarkable Organ in Eudendrium ramoswin .. sae ss 
Siphonophora of the Bay of Naples... .. 2+ + +s 
Ctenophora of the Bay of Naples 


Symbiosis of Lower Animals with Planis.— Yellow Cells of Radiolarians 


and Celenterates.. .. Be Seb 
New sub-class of Infusoria—(Pulsatoria). AACR TRL ee 
Skeleton of the Radiolaria .. 1. .. an we tee we 
Recent. Researches on the Helga iota ee 
Dimorpha mutans.» 
Contributions to the Knowledge of th the Amba (Plate TL) 3) 
Protozoa of the White Sea... -. Bee Cisse led fs abe ee 


BorTany. 
Free Cell-formation in the Embryo-sac of ree aed 
Structure and Division of the Vegetable Cell. ais 
Fertilization of Apocynacez  .. Mee ee 
Cross-fertilization and Distribution of Seeds . 


Swelling of the-Pe@ <0 ie cee ee Nay) aw oe ee ae 
Aril of Ravenala.. . ASAP NSE? oer bon wrth Arc 
Structure and Mechanics of ‘Stomata EEE REE Deen Er 
Callus-plates of Steve-tubes Sere bok eee iiwae te 
Phyllomice Nectar Glands in Poplars BED rh erat caine 
Histology of Urticacez A 


Structure of Podostemonacez «ss. ss ae we ote 


Pitchers of Cephalotus follicularis .. 2. se +0 +5 = 


Action of Light on Vegetation .. oP 
Production of Heat by Intramolecular Respiration. Ngee ae 
Physiological Functions of Baia le a sacle 
Metastasis ..  .. Pacer t ats beer eee 
Phosphorescence in Plants. CA PACE, Oe erty 
Transformation of Starch . 

Occurrence of Allantoin in the Vegetable Organism 
Ezcretion of Water on the Surface of Nectaries .. 


«8 (ee 
ee 
e 


Determination of the Aciaty. of Assimilation by the Bubbles given 


under water... -. PE EN eA ter aap eens 


| Detmer’s Vegetable Physiology... .. sc sw ss wee 


Development of Sporangia.. .. ss «2 se e eines 
Lenticels of the Marattiacer _.. Bie Caper Rae eer 
Stomata in the Leaf-stalk: of Filiciner |. 


_ Adventitious Buds.on the Lamina of the Frond of Asplenivm bulbiferum 5 
. - Anatomy and Classification of Schizwace@ 1. .» se 
-. Biological peculiarity of Azolla carolintana ., +. «sss 


Female Receptacle of the Jungermanniez Geocalycex .. + 
Vegetative Reproduction of Sphagnum 0.5 ss ee on os 


_ Action of Light on Fung iomt saan ap 


Chemical Nature of the the Cell-awall in “Fungi Svar Ueceel oes 
“ Mal nero” of the Vine... . Sirah ie Boies ges Ap 
Roesleria hypogzxa parasitic on the Vine een ee hee 


eta Didymosphzria and Microthelia .. 4. eos bg 


Peronosporer and. Saprolegniee 10 ss an nee 


. Fungi in Pharmaceutical Solutions .. .. oe be ie 


Vegetable Organisms in Human Excrements s+ we 0s 
Saccharomyces apiculatus .. 0 16, cee ee ne ee 


| Etiology of Malarial Fevers .. SS awit pace eres 
-. Aktinomykosis, a new Fungoid Catile-Disease Fea aes ee 
Infection by Symptomatic Anthraz .. ie 
. Experiments on Pasteur’s Method of Anthrax-Vaccination .. 
Duration of Immunity from Anthraz — -s we we ee 
Sip pe Method of Vaccination for Foul-cholera, gt ee eek 


oe. ve oe oe o* 
. 


“Nutrition of Lichens .... PIR ig Bah Aas Ma 
- .. Thallus of Usnea articulata .. 2 
Tanta at aetin of. Lower Animals with Plants” 


os 


°° 


oe 


ee 


oe 


Ook, 


Summary or Current Ruszarnouss, &c.—continued. 
* Yellow Cells” of Radiolarians and eigite ny et Sok Gab. 1 toe eee 


Cooke’s British Fresh-water Algz ..  .«- Te UB ae ys: 

Diatoms in thin Rock Sections .. RM ANN 7 

Fineness of Striation as a Specific Character of Diatoms sie 

Schmidt's Atlas of the Diatomacex .. +. APES EP aR 

““ Aphaneri” —Ezamination of Water .. «+ «+ en te eee aw 
Microscopy. : 2 

oi Aope ” Class Microscope (Fig. 29) Bd Sf ATT Se aoe aa 


Brownings Portable Microscope (Figs. 30 ‘and '31)- 
Harting’s Binocular Microscope (Figs. 32 and 33) ays, pea eR RT a 
Nachet’s Double-bodied Mieroscope-tube (Figs, 34 and 3 Sas “955 4 
Wenham’s Universal Inclining and Rotating Microscope (Plate Iv ) igs a ae 
36-39) . 25 
Bausch and Lomb Optical Co? 8 : Trichinoscope (Figs. 40 and 41). ge: a 
“ Hampden” Portable Simple Microscope (Figs. 42 and 43) BRN Fan ert. 
Excluding Extraneous Light from the Microscope...  .. «+ + ## es ‘ 
Nachet’s Improved Camera Lucida (Figs. 44-46) wa’ = sav schon a Rie 


Abbe’s Camera Lucida (Fig. 47) Be eae Pi Mom etm ace 1} 
Curtis’s Camera Lucida Drawing Arrangement SS i Sc eae ge ee 
Drawing on Gelatine with the Camera Lucida «. oo, 262% 
Tris-Diaphragm for varying the Aperture of Objectives (Figs. 48 ‘and 49). oa ee 
Gundlach 4-inch Objective... .. Brice eed 
Scratching the Front Lenses of Homogencous-immersion Onjctives Fe the 
Fluids for Homogeneous Immersion... .. S5IN each owas Sage 
Advantage of Homogeneous Immersion se os iy iter Seam h nee 
Vertical Illuminator for examining Histological Elements oa tet weet ae, 
Grifith’s Parabolic Reflector .. +e +4 + SPRL Ag 7 2 
Forrest’s Compressorium (Fig. 50). Wi tea peek as 


Julien’s Stage Heating Apparatus (Figs. 51 and 52) 7 

Beck’s Achromatic Condenser for Dry ot Immersion Onjectivs Gigs, 53. 
and 54).. ee we 

Pennock’s Oblique ‘Diaphragm (Fig. 55) 

Stereoscopic Vision with Non- -etereoscopic Binocular Areongeuiente (Figs. a 


56-58) . eB SS hae ee ee ama 
Injection of Thvertebrate ipa C2 LES SO Ae, arenas 
Cold Injection Mass .. +. BAT ete AORN Lire so ae 
Staining with Saffranin .. Bocce ae CNS oy 0 ie ee 
Staining with Silver Nitrate .. PRR SE ar pW aN et ty GSN TE a SP. 
Staining Tissues treated with Osmic NAotd © ace eee a ee Se 
Mounting the «‘ Saw” of the sda kink aca SAG ie winhn nse oleh, see iene ‘3 

= Mounting Butterfly-scales ..  .. CP gh te ae en a 
Imbedding Ctenophora _.. PROMABr MEL We keerse sin oc 
Staining Living Protoplasm with Bitmarck Brown... ad heat Se 


' Preservation of Infusoria and other Microscopical Organisms Sash gpa teen 
Staining the Nucleus of Infusoria .. 1. 16 ne te te eee ge 
Aniline Dyes and Vegetable Tissues .. vo) laser Aiea” [oe hte Figeree 
Indol as a reagent for Lignified Pultmenbiens bone ext 

- English’s Method of Preserving Hoorn and Wild Flowers pe 
- Mounting Salicine Crystals _.. per, sae Ne Bel 
_ Bausch and Lomb Turntable (Fig. 59) . AG igh Sigh ek ae age 

Griffith Cell. pole intew Nee. Ar pene, f Vx hie Lg sie ti 
Bausch and Lomb Circle Cutter (Fig. 60) Fe Ce Af Negras 
Wax and Guttapercha in Dry Mounting... 2. +s ee ee 
Aeration of Aquaria “ oo ee ee se rs - se ee Tepe 


PROCEEDINGS OF THE Soomry Pe aeee ct ae alee a We ene eae 
Treasurer's:Account. §< 4,0 avi ee Se ae Oe ae 
Report of the Council ©... ee 2 


C53 
Royal Atlicroscopical Society. 


, MEBTINGS FOR 1882, 


At 8 P.M. 


1882. Weditcdday; JANUARY << 1650 ' re. auch bce AL 


FPRBRUARY ... . é P 8 


(Annual Meeting for Election - ise 
and Council.) 


>) ae 


WEG or Se a a ie See ay cate eo 
PRPTNG Sie he Be Aas Sag ae ce mia olen EO 
DER eng iol pas ac Re Soa tak Aa 
PUNK Sy cece ee Pe ee a ene AAS 
es OCTOBRE 0 os sieht aier a ge eg AL 
»  Novemsrr SPE EEN ee ER les 7 
DECEMBER ae spi WS in Uae eee ap ke 


"THE “ SOCIETY » STANDARD SCREW. 


a ‘The Council lave made arrangements for a fatihice scans of Gauges - 
and | Serew-tvols for the “ ‘Socrery ” STANDARD Screw for OBJECTIVES. 


ic The price of the set (eousiatins of Gauge and pair of Screw-tools) is 

12s 8. 6d. (post free 12s. 10d.). Hpplications. for sets should be made to the 
istant-Secretary. cp 

es For an ‘explanation of the intended use of the ginge, see i onal ie the — 

8 ay} ee PP. 548-9. . | 


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COUNCIL. 


ELECTED 8th FEBRUARY, 1882. 


PRESIDENT. 
Pror. P. Martin Dunoan, M.B., F.R.S. 


VICE-PRESIDENTS. 


Pror. F. M. Batrour, M.A,, F.R.S. 

Rosert Brarrawairs, Esq., M.D., M.B.C.S., F.L. Ss. 
Rosert Hopson, Esq., F.RS., F.LS. 

JoHN Ware Srepuenson, Hsq., F,R.AS. 


ee Sat RRC eg is Se eae tee a NG Oe 5g ati ¢ aA 
OTL Mae SR Ne ER EET BT Cee Pet Mant YAO, ETE ee RIN oe SY Cig 


TREASURER. 
Lions 8. Bratz, Esq., MB, FRCP. ERS. 


SECRETARIES. 


‘Caarres Srawarr, Esq, MLB.CS., F.LS. 
Frank Crisp, Esq., LL.B, BA, V.P. & Treas. LS. 


Twelve other MEMBERS of COUNCIL. 


Lupwie Dreyros, Esq. 

Cuartes James Fox, Esq. 

James Guaisner, Hsq., F.RS., F.RAS. 
J. Wiut1m Groves, Esq. 

A. pe Souza GUIMARAENS, Esq. 

Joun E, Inapen, Esq. 

Joun Mayatn, Esq., Jun. 

Ausert D. Micmarn, Esq., F.LS, 

Joux Miran, Esq., L.R.0.P.Edin., FLS. 
Wit11am Tuomas Surroux, Esq. 
Freperiox H. Warp, Esq., M.R.CS. - 
a CaanTErs ee mie MRCS, ALS. 


OE fee) 


I. Numerical Aperture Table. 


“ ApgRTURE” of an optical instrument indicates its greater or less capacity for receiving rays from the object and 
transmitting them to the image, and the aperture of a Microscope objective is therefore determined by. the ratio 
between its focal length and the diameter of the emergent pencil at the plane of its emergence—that is, the utilized 
“diameter of a single-lens objective or of the back lens of a compound objective. 

his ratio is expressed for all media and in all cases by m sin wu, m being the refractive index of the medium and w the 
mi-angle of aperture. The value of m sin u for any particular case is the ‘numerical aperture” of the objective, 


Angle of Aperture (=2 1). Theoretical P 
Iw ical Ilumi-| Resolving |; hg 
Dry and Immersion mneriica Water- | Homogeneous-| nating Power, in TRUDE, 
bjectives of the same Gh ae i bare Okie. Immersion| Immersion | Power. | Lines to an Inch,| FOWe 
___ Power G in.) Hi hyp OBI ives: | Objectives,| Objectives. | (a2.) | (A=0°5269y (2 ) 
m.0°50 to 1-52 N. A. @=1) \m= 1:23.) (nm = 1°52.) =line E.) a 
oe a 180° 0’ |2°310) 146,528 "658 


me 161° 23’ |2°250|. 144,600 *667 


153° 89’ |2°190| 142,672 “676 
Z 147° 42’ |2-132| 140,744 “685 
a 142° 40’ 138,816 694 
fe 138° 12! | 136,888 “704 
as 134° 10’ 134,960 -714 
ew 130° 26’ 133, 032 725 
126° 57’ | 131,104 “735 
123° 40’ 129,176 -746 


180° 0’|}. 122° @’ 
on 165° 56’| 120° 33’ 
EP 155° 38’) 117° 34’ 
ce 148° 28’| 114° 44’ 
oh 142° 39’| 111° 59’ 
oe 137° 36’; 109° 20’ 
se 133° 4’| 106° 45’ 
ae 128° 55'| 104° 15’ 


074 

016 

960 

904 

850 

796 

770; 128,212 "752 
742 | 127,248 "758 
-690| 125,320 *769 
638 

588 

538 

488 

440 

392 

346 

300 


123,392 | °781 
121,464 | «794 
119,536 | 806 
117,608 | +820 
115,680 | °833 
113,752 | °847 
111,824 | +862 
109,896 | 877 
-254| 107,968 | °893 
-210| 106,040 | +909 
166} 104,112 | -926 
-124| 102,184 | -943 
! 082} 100,256 | -962 

y 100° 10'/| 84° 18’ |1-:040| 98,328 | ~-980 
180° 0’ | 97° 31’) 82°17" |1:000| 96,400 | 1-000 
157° 2 | 94° 56/| 80° 17'| -960| 94,472 | 1-020 ~ 
147° 99' | 92° 24’! 78° 20'| +922) 92,544 | 1-042 
140° 6’ | 89° 56’) 76° 24’ | +884) 90,616 | 1-064 
133° 51’ | 87° 32’| 74° 30’| -846| 88,688 | 1-087 
128° 19'| 85° 10’) 72° 36’| +810} 86,760 | 1-111 
123° 17'| 92° 51’| 70° 44’ | -774| 84,832 | 1-136 
118° 38’| 80° 34’) 68° 54’ | °740| 82,904 | 1-163 
114° 17’| 78° 20’, 67° 6'| +706} 80,976 | 1-190 
“110° 10’ | 76° 8'| 65° 18’ | *672| 79,048 | 1°220 
106° 16' | 73° 58’| 63° 31’ | °640| 77,120 | 1-250 
402° 31’ | 71° 49'| 61° 45' | 608} 75,192 | 1-282 
9g° 56'| 69° 42’, 60° 0/| -578| 73,264 | 1-316 
95° 99° | 67° 36'| 58° 16" | -548| . 71,336 | 1-351 
92° 6’ |. 65° 32} 56° 32’ | -518| 69,408 | 1-389 
-gg° 51" | 68° 31’| 54° 50’ | +490) 67,480. | 1-429 
85° 41’ | 61° 30’| 53° 9’ | -462| 65,552 | 1-471 
92° 36 | 59° 30'|. 519-28’ | -436| 63,624 | 1-515 
79° 35' | 57° 81'| 49° 48" | -410| 61,696 | 1°562 
76° 38’ | 55° 34’| 48° 9" | +884) 59,768 | 1-613 
73° 44’ | 58° 38’| 46° 30'| °360| 57,840 | 1-667 
"70° 54’ | 51° 42"| 44° 51’ | +336) 55,912 | 1-724 
68° 6’ | 49° 48’). 43° 14" | «314| 53,984 | 1-786 
65° 22' | 47° 54’! 41° 87" | +292) ~ 52,056 | 1-852 
62° 40' | 46° 2| 40° 0'| -270; 50,128 | 1-923 
60° 0’ | 44° 10’| 38° 24’ | -250/ 48,200 | 2-000 


Oe oak ee 


COPADOCW HAD OW HADOWHADOWHADOWHADOOHAMOWHKADOWVWHADOW 


w. . }125°° 8" ¥01° 50° 
.. [121° 26'| 99° 29° 
EO TIBS 00!) O72 AL 
.- | 114° 44’) 94° 56" 
.» | 111° 86’| 92° 43° 
 _|108° 36} 90° 33’ 
{105° 42’| 88° 26' 
wo |109°-53’| 86° 21’ 


° 


 AAAAADHADDOAIAIIIAIDHDHHDDOHOOOSOOSOOH EH ERD 


Pe tet pe ede ke ek ek et et et et et et et et et BODO EO DO 
Ty ER APRN SRR Ta EN SEEDY AAS IBLE pas 


SECTS (oie al ole sich tale unless eirkenirek nininanl Crane ena 


2009900000006 


PLE.—The apertures: of four 

ould be compared on the angular aperture view as follows:—106° (air), 157° (air), 14 
‘actual apertures are, however,.as ; ‘ len «3 eth}: Stuy nape 
“tiumerical apertures, § =! ; 


objectives, two of which are dry, one water-immersion, and one oil-immersion, 
2° (water), 130° (oil). 
26. ~-.» 1°38 or their 


CA? 


II. Conversion of British and Metric Measures. 


1.) LinkAL. 
Scale showing Micromillimetres, §c., into Inches, fc, 
y Peta “ ins. mm. ins. | mm. ins. 
&c., to Inches. 1 :000039| 4 -039370| 51 2007892 
? 
“ine 2 -000079| 2 “078741 4 pe 
3 000118| 38 118111 08663: 
Pe ats. 4 -000157| 4 -157482| 54 2- 126008 
5 :000197| 5 “196852 | 55 2: 165374 
= at] 6 -000236| 6 “236223 | 56 2204744 
ae 7 -000276|° 7 275593 | 5'7 2°244115 
= ml 8 +000315| 8 -314963 | 58 2+283485 
le | 9 +000354| 9. “354334 | 59 2- 329855 
aoe | 10 -000394! 10(1cm.) -393704| 60 (6cm.) 2°362226 
E z| 11 -000483| 11 | 433075) 61 2°401596 
A 000472 - 472445 ag meet 
el 3 +000512 ‘511816 480337 
= 8 
=f 14 -000551| 14 “551186 | 64 2+519708 
Be 15 -000591| 15 -590556 | 65 2°559078 
jeu 16 -000630| 16 “629927 | 66 2°598449 
Rie 8 17 -000669| 17 “669297 | 67 2637819 
is s| 18 000709 i “708668 ae 2077188 
=e 19 000748 *748038 “71656 
lz H| 20 +000787| 20 (2em.) +787409| 70 (7em.) 2-755930 
Jes 21 -000827| 21 ‘826779 | ‘71 2°795801 
E zl 22 “000866 | 22 “866150 ie gener 
=m -000906 | 23 -905520 2874042. 
iE z| 24 000945 24 “944890 74 2-913412 
=5 5 000984 | 25. -984261 2+952782 
=e 26 -001024| 26 1023631 | 76 - 2°992153 
lz 3 27 -001063 | 27 1:063002| 77 3°031523 
BS 28 -001102| 28 1:102372| 78 -  8:070894 fe 
el 29 -001142| 29 1°141743| 79 3:110264 as 
Es 30 +001181| 80 (80m,)1:181113| 80 (Sem) 3:149635, Aj. 
Ee 31 -001220| 31 1:220483| 81 3°189005 | ve 
=a 32 -001260| 32 1°259854 | 82 3:228375 |. as 1 
E | 33 *001299| 33 1°299224 | 83 3°267746 | tz. 2! 
aS 34 :001339 | 34 1:338595 | 84 3°307116| we 72% 
[ze 35. 001878 | 35 1°377965 | 85 3346487] «OE 
= 86 -001417| 86 1:417336 | 86 3°385857 2 ae 
[Em 37 :001457| 37 1°456706| 87 3°425298 | oats = 
=e 838 001496 | 38 1:496076 | 88 3°464598 |. $970 
jes 39 -001535| 39 1°535447 | 89 3:503968| + 6°34 
cE | 40 -001575| 40 (4om.)1:574817| 90.(9cm.) 3:543389] ae 7 
=m 41 -:001614| 41 . 1°614188| 91 RRP AL ISR api ag I os 
Pe 2 42 -001654| 42 1°653558 | 92 3°622080|. i» 1, 
=5 43 -001693| 48 1-692929 | 98 3°661450 | x 
Es 44 +001732| 44 1°732299 | 94 3*700820} 2. 
WEE 45 -001772| 45 1°771669 | 95 3740191 | 
| (Be 46 001811} 46 1°811040| 96 3°779561| 1 
ze 47 -001850| 47 -1°850410| 97 3°8189382| 3s 
= |. 48 +001890| 48- 1889781 | 98 _ 8858302} 
lz | 49 +001929| 49 1:929151' 99. 3-897673 |. 
s8 5O +001969 | 50 (5em.)1:968522 1100 (10 om,=1 decim.)| 
[El 60 -002362 n eee ie ef 
[E + 70 002756 decim. Te eA 
SE 80 -003150 1 ~ 8+937043 
lee 90 003543 2 - 1+874086 
| 100 = -003937 3 11°811130 © 
[zs 200 007874 al 15+748173 
=n 800 -011811 5 19°685216 
[zs 400 +015748 536 ~ 93-622259 
500 -019685 "7 277559302 
Bee 600. -023622 8 31496346 
10002 =1mm, 700 -027559 | 9 35-483389 
10 mm.=1 em. 800 -:031496 10 (1 metre). $9°370432 


10cm. =1dm, | 900 *035438 = 3-280869 ft. 
10 dm. =1 metre. | 1000 (=1 mm.) ' a = 1093623 yds, 


*SOTMUIBIDOTTY 


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( 10°) 


III. Corresponding Degrees in the 
Fahrenheit and Centigrade 


Scales. 

Fahr. Cent, Cent. Fahr, 
° ° ° ° 
500 260° 0 100 212°0 
450 232°22 98 208°4 
400 20444 96 204°8 
350 176°67 94 201-2 
300 148°89 92 197°6 
250 V2 90 194:0 
212 100°0 88 190°4 
210 98°89 86 186°8 
205 96*11 84 183°2 
200. 93°33 82 179°6 
195 90°56 80 176°0 
190 87°78 78 172°4 
185 85:0 76 168°8 
180 82°22 74 165°2 
175 79°44 72 161°6 
170 76:67 70 158:0 
165 73°89 68 154°4 
160 7111 66 150°8 
155 68°33 64 147°2 
150 65°56 62 143°6 
145 62°78 60 140-0 
140 60°0 58 136°4 
135 57°22 56 132°8 
130 54°44 54 129°2 
125 51°67 52 125°6 
120 48°89 50 122-0 
115 46-11 48 118°4 
110 43°33 46 114°8 
105 40°56 44 111°2 
100 37°78 42 107°6 

95 35:0 40 104-0 
90 32°22 38 100°4 
85 29°44 36 96°8 
80 26°67 34 93°2 
75 23°89 32 89°6 
70 21-11 30 86°0 
65 18°33 28 82°4 
60 15°56 26 78°8 
55 12°78 24 75°22 
50 10:0 . 22 71°6 
45 7°22 20 68:0 
40 4°44 18 64°4 
35 1°67. 16 60°8 
32. 0:0 14 Se Uf fey 
30 — — iil 12  53°6 
25 — 3°89 10 50°0 
20 — 6°67 8 46°4 
15 — 9:44 6 42°8 
10 — 12°22 4 89°*2 
5 — 15:0 2 35°6 
ra) — 17°78 oO 32-0 
—- 5 — 20:56 | — 2. 28°4 
— 10 — 23°33 | — 4. 24°8 
— 15 — 26°11 | — 6 21°2 
— 20 — 28°89 | — 8- 17°6 
— 25 — 31:67 | — 10 44: 
— 30 — 34:44 | — 12 10° 
- 85 — 37°22 | — 14 6" 
— 40 — 40:0 -— 16 3° 
— 45 — 42:78 | — 18 — 0° 
— 50 — 45°56 | = 20 — 4° 


Linseed oil (sp. gr. *932) 


Oil of turpentine (sp, gr. 886) 


Air 


IV. Refractive Indices, Dispe 
Powers, and 
Angles. 


(1.). Rerractive Lypices. 


Diamond 
Phosphorus 
Bisulphide of carbon 
Flint glass 

Crown glass 

Rock salt 

Canada balsam 


Oil of turpentine (sp. gr. *885) 
Alcohol 

Sea water 

Pure water 

Air (at 0° C, 760 mm.) © 


(2.) Dispersive Powers. 


Diamond 
Phosphorus 
Bisulphide of carbon. 
Flint glass 
Crown glass ath 
Rock salt TR ee 
Canada balsam e 
Linseed oil (sp. gr. +932) 
Oil of turpentine (sp. gr. *885) 
Aleohol “: 
Sea water 
Pure water 
Air sae 
(3.) Povarizinc ANGLES. — 
Diamond 
Phosphorus 
Bisulphide ef carbon 
Flint glass Pees tt saa 
Crown glass© = EAD 
Rock salt A riee ass 
Canada balsam < 
Linseed oil (sp .gr, 932) 


Alcohol 
Sea water 
Pure water. 


MaAcuiryine Power, 


V. Table of Magnifying Powers. 


«il ) 


EYE-PIECES. 


Beck’s 2, 


Beck’s 1, | Powell’s 2, Beck’s 4, Beck’s 5 
Powell’s 1, and Powell’s3.| Ross’s C. | Beck’s 3. | Powell’s 4, Rose's E. Powell’s 5.] Ross’s F. 
Ross's: A | Ross's B; Ross’s D. 
» mearly.* 
Focau LENGTH. 
2 in. 1 in, | lin, | 4in, | 2in. | din. | pin. | Fim. | Pin 
MaAcGniryinG Power. 
5 7 | 10 | 12.15 20 | 25 | 30 | 40 
AMPLIFICATION OF OBJECTIVES AND EYE-PIECES 
' COMBINED. 
15 20 25 30 40 50 60 30 
182 25 312 374 50 - 622 715 100 
25 331 412 50 662 832 |. 100 1334 
373 50 62% 79 100 125 150 200 
50 662 832 100 1332 1662 200 2662 
75 4 100. 125 150 200 250 300 400 
932 | -125 156% 187% 250 3122 | 375 500 
100 1332 1662 200 2662 |. - 3331 400 5334 
1123 150 187% 225 300 375 450 600 
150°} ~~ 200 250 300 400 500 600 800 
1874 250 3122 375 500 625 - 750 1000 
225 300 - 375 450 600 750 900 1200 
250 9 3832 4162 500 6662 8332 | 1000 13332 
300 400 ~500 -600 800 1000 1200 1600 
370, 500° 625. 750 1000 ‘1250 1500 2000 
450 600° 750 900 1200 1500 1800 2400 
525 700 875 - | 1050 1400. 1750 2100 2800 
* 600 ~ 800 1000 |» 1200 1600 2000 | 2400 3200 
- 675 900 *| 1125 1350 1800 .} 2250 2700 3600 
750 1000 “1250 1500. | 2000 2500 3000 4000 
825 | 1100 |} 1375 | 1650 2200 2750 3300 4400 
900 | 1200 | 1500’ | 1800 | 2400 | 3000 | 3600 | 4800 
975 “1300. 1625 1950 2600 3250 3900 5200 
1050 1400 1750 2100 2800 3500 4200 5600 
|. 1125 | 1500 | 1875 | 2250 | 3000 | 3750 | 4500 | 6000 
1200 1600 2000 2400 _| 3200 4000° 4800 6400 
1275 1700 2125 2550 3400, 4250 5100 6800 
1350 | 1800 2250 2700 3600 4500 | 5400 7200 
1495 1900 2375 2850 3800 4750 | 5700 7600 
1500 2000 2500 3000 4000 5000 6000 8000 
| 1875 2500 3125 8750 5000 | 6250 7500 {10000 
| 2250 3000 3750 4500 | 6000 7500 9000 | 12000 
3000 4000 -5000- 6000 } 8000. | 10000 } 12000 } 16000 
- 8750 4F- 5000 6250 7500 $ 10000 4} 12500 | 15000 fF 20000 
4500 6000 | 7500 9000 } 12000 § 15000 | 18000 | 24000 
| 6000 10000 | 12000. | 16000 } 20000 | 24000 } 32000 


8000 


* Powell and Lealand’s No. 2= 7-4, and Beck’s No. 2 and Ross’s B = 8 magnifying power, or 
z a respectively 7}, less and Yr More than the figures given in this column. 


Un 7 ee 8 
HENRY CROUCH’S 


First-Class Microscopes, 


Student’s Microscope. 


New Family and School 
Microscope. 


New Series of Objectives, | 


Wew Accessories, 


haw 


NEW ILLUSTRATED CATALOGUE, ON RECEIPT OF STAMP. MAILED: ABROAD FREE. 


Peet ate 


HENRY CROUCH, 66, Barbican, London, E 
(i ieabere sor Binepioay ose be nae ge 


JAMES W. QUEEN & C0., 924, Chostnut Street, Philadelphia, T.8, 


JOURN. R. MICR. SOC. SER. II. VOL. II. PL. IV. 


Wenham’s Universal Inclining and Rotating Microscope. 


JOURNAL 


OF THE 


ROYAL MICROSCOPICAL SOCIETY. 


APRIL 1882, 


TRANSACTIONS OF THE SOCIETY. 


~ IV.—The President's Address. By Prof. P. Martin Duncan, 
M.B. Lond., F.RB.S., &e. 


(Annual Meeting, 8th February, 1882.) 


My first and saddest duty in addressing you this evening, is to re- 
cord the names of those who have passed away from among us 
during 1881. These are:—C. J. H. Allen, H. H. Bigg, Sir A. 
Brady, R. C. Griffith, T. E. W. Knight, W. Moginie, HE. B. 
Pitchford, F. Symonds, and J. Tennant. 

Of some of these we have not received any obituary notices ; 
those which have been sent to us will be printed in our ‘ Pro- 
ceedings.’ 

While we regret the loss of so many of our Fellows, it is satis- 
factory to turn to the list of elections into the Society, and to find 
that, as stated in the Council’s Report, we now have more Ordinary 
Fellows than at any previous period. In 1867 the numbers 
reached 452, but soon after that date, each year showed a falling off, 
until in 1878 there were less than 400 Fellows. In the three 
subsequent years there has been a large increase (after deducting 
all deaths and retirements), so that the present number is in excess 
of 500. Whether that total shall be again reduced, depends very 
much upon the influence which the Fellows may exert upon their 
friends and others, to induce them to join our ranks. I need 
hardly say that every addition enables us to increase our usefulness. 


The Report of the Council contains an expression of passing 
regret that the Society is not furnished with the results of more 
original work on the part of its Fellows. It is, I] know, often 
assumed that we have been worse off in this respect in later years 
than formerly, but if you will turn to the presidential addresses 
for 1855 and 1856 * (those of Dr. Carpenter) you will find that 
he gives expression to the same complaint, and in very strong 


* Trans. Micr. Soc, Lond., iii. (1855) pp. 39-40; iv. (1856) pp, 17-21, 
Ser. 2.—Vok. II. L 


146 Transactions of the Society. 


terms. Judging from his remarks, I should conclude that so far 
from having retrograded, we can show a substantial advance. Apart 
from the valuable papers on the Optics of Microscopy, to which I shall 
refer more in detail, we have had communications read at our 
meetings during the past year which were both interesting and 
important. The description of the beautiful Rotifers Gicistes Janus 
and Floscularia trifolium, by Dr. C. T. Hudson; Mr. Michael's 
description of the singular Acarus Dermaleichus heteropus, parasitic 
on the Cormorant ; the notice of the remarkable disks of sulphide of 
iron found in the Londen clay and which are pseudomorphs of the 
silicious tests of Coscinodisci and other Diatomacee, by Mr. W. H. 
Shrubsole and Mr. F. Kitton; and the description of a supposed 
new boring Annelid, Lithognatha worslet, by Mr. Stewart, are 
papers which do credit to the authors. 

When we consider, moreover, the large number of observations 
recorded during the past year by the various Societies which receive 
communications principally worked out by means of the Micro- 
scope, it cannot fail to be recognized that the activity and progress 
of microscopy are greater now than at any former time, and that the 
tendency is to still further increase. The most valuable part of our 
bi-monthly Journal is the summary which it contains of this stupen- 
dous amount of original work. The Microscope is moreover always 
being carried into new fields. It now promises to be of great 
assistance to the chemist, and while but a few years ago no one 
thought of including it among the essential tools of the geologist, it is 
extensively applied at the present time to the examination of rocks, 
and most valuable results have been brought to light by its aid. 
Instead then of allowing ourselves to be tempted to bemoan the 
“stagnation of microscopy ” we, as a Society devoted to its study, 
may congratulate ourselves and the rest of the scientific world, 
that whether as regards theory or practice—the optical and 
mechanical or the observational part of our science—there has never 
been a time when so much evidence could be produced of solid 
progress as now. 

Whilst we can, I think, usefully devote a little time in each year 
to the consideration of the results obtained in the previous one, it 
would be difficult within the compass of one annual address to deal 
with both branches of microscopical work ; and therefore (the Society 
having done me the honour to elect me to the presidential chair 
for another year) I must reserve for a future occasion a notice of 
the discoveries in the animal, vegetable, and mineral worlds, which 
the Microscope has been the means of bringing to light since the 
commencement of the present decade. ‘The adoption of this course 
is also supported by the fact, that the past year has been, I think, 
specially marked out by the important points in microscopical optics, 
which have, for the first time, been elucidated. In no previous year, 


The President's Address. By Prof. P. Martin Dunean. 147 


so far as I can gather from a reference to the printed records of the 
Society, has so much light been thrown upon subjects which are of 
the first importance in microscopy. 

I propose, then, briefly to recall the evidences of progress in 
this part of our science, which the past year affords. 


The Abbe Theory of Microscopical Vision. 


As a notable feature may be mentioned the greatly increased 
interest which has been awakened in the important contribution to 
the theory of the Microscope, originated by our illustrious Fellow 
Professor Abbe. Although those views are now several years old, 
and were brought before the Society so long ago as 1877 by our 
then Treasurer, Mr. J. W. Stephenson, the recognition of the extra- 
ordinary nature of the experiments, was until lately confined to a 
very small circle. Both in this country and in Germany and 
America, however, the past year has seen a great extension in the 
number of those who have followed these experiments, and who 
have appreciated the important bearing which they have on 
microscopical vision. 

I have used the term “extraordinary ”* because I think that 
every one who has seen these experiments will readily agree that it 
is extraordinary, in every sense of the word, to find, that merely by 
excluding a greater or less number of the “ diffraction” images 
found at the back of the objective, a great variety of entirely 
different appearances are presented by one and the same object— 
lines at a known distance apart doubled and quadrupled,—or that 
objects in reality quite unlike can be made to seem identical— 
multi-sided figures giving images of squares. In short, the same 
objects may appear to be different in structure and different objects 
may seem to be zdentical, entirely according as their diffraction 
images are made dissimilar or similar by artificial appliances 
between the objective and eye-piece. The appearance of particular 
structure can even be “ predicted ” by the mathematician, before it 
has been actually seen by the microscopist. 

The result of these experiments is to show that a distinction 
must be drawn, between the vision of minute objects and what may 
be termed, for this purpose, “coarse” objects, i.e. those which are 
considerable multiples of the wave-lengths. 

The latter are imaged by the Microscope, substantially in the 
Same way as by the camera or the telescope, and their images cor- 
respond point for point with the object. We are therefore able to 
draw the same inferences as to the actual nature of such objects, as 
in the case of ordinary vision. 

Minute objects, or parts of objects, only a few multiples of the 
waye-lengths, are, however, imaged in an entirely different way, viz. 

L 2 


148 Transactions of the Society. 


by the diffracted rays produced by the action of the minute struc- 
ture. If all the diffracted rays from the object are reunited and 
reach the eye, an image of the real structure is obtained. If some 
only of the rays are transmitted, the image is no longer necessarily 
a true representation of the object, and the smaller the admitted 
portion the more incomplete and dissimilar the image. Now as the 
objects become more and more minute, the diffracted rays are more 
widely spread, and fewer of them can be admitted by an objective 
even of largest aperture. The visible indications of structure in such 
images are not therefore necessarily conformable to the actual nature 
of the object under examination, and the only inference that we are 
entitled to draw from the image as presented to our eye, is the 
presence, in the object, of some of the many different structural pecu- 
hiarities which are capable of producing the diffraction phenomena 
observed in the particular case. 

Our veteran microscopist, Dr. Carpenter, C.B., has embodied, in 
the edition of his widely known work published during 1881, a 
statement of the leading points of the diffraction theory, which is 
valuable as containing the results of his own matured views on the 
subject. He says (p. 187), “This doctrine, originally based on 
“elaborate theoretical investigations in connection with the undu- 
“ latory theory of light, has been so fully borne out by experimental 
“ inquiries instituted to test it, and is in such complete harmony 
“ with the most certain experiences of microscopists, that its truth 
“ scarcely admits of a doubt.” 

There are one or two points that require to be kept prominently 
in mind in regard to the diffraction phenomena in question; 
1st, that they are not to be confounded with the so-called “ diffrac- 
tion band” observed round the outlines of objects illuminated by 
oblique light, nor with the “diffraction ” rings displayed by bril- 
liantly illuminated globules; 2nd, that they are not confined to 
transparent objects illuminated by transmitted light, but are also 
produced by opaque objects ; and 3rd, that they are not limited to 
lined or regular objects, but extend also to zrregular structures or 
isolated elements of any shape; in fact universally, to structures of 
all kinds, whenever the uniform propagation of the luminous waves 
is disturbed by the interposition either of opaque or semi-opaque 
elements, or of transparent elements of unequal refraction, which 
give rise to unequal retardations of the waves. They therefore 
apply not merely to the “resolving power” of objectives, but to 
their general delineating power—the power of the Microscope to 
show things “as they are.” 

The 3rd point is, I need hardly say, most important, and one 
which it will be very interesting to have more fully elucidated, 
having regard to Professor Abbe’s statement that objects (such as 
the flagella of Bacteria) which are only a fraction of a wave-length 


The President's Address. By Prof. P. Martin Duncan. 149 


in diameter, will necessarily appear to us, not in their proper 
proportions, ‘but with greatly increased diameters, and that very 
minute striations must appear as if the dark and bright interspaces 
were nearly of equal breadth, although in reality not 80. 

There are obviously many histological problems, such as the 
question of the structure of muscle, which a proper knowledge of 
this part of the subject may greatly help to elucidate. 

The facts which we now have before us in regard to microscopical 
vision, are sufficient to justify the injunction of Professor Abbe that 
“the very first step of every understanding of the Microscope is 
to abandon the gratuitous assumption of our ancestors that micro- 
scopical vision is an imitation of macroscopical, and to become 
familiar with the idea that it is a thing sw generis, in regard to 
which nothing can be legitimately inferred from the optical 
phenomena connected with bodies of large size.” ‘That there must 
_ be a great deal more yet to be elaborated in regard to the origin 
and nature of the phenomena we have been considering, is obvious, 
and I hope that the attention of our own physicists and microscopists 
will be directed to a subject of such extensive practical bearing, not 
merely to the theoretical microscopist, but to the large class of 
practical histologists who are entirely dependent upon the Micr oscope 
for the accuracy of their observations. 


The Aperture of Objectives. 


99 


The “aperture question,” as we all know, gave rise, several 
years ago, to a somewhat acrimonious controversy, not in the 
‘ Proceedings’ of the Society, but in the unofficial section of its then 
Journal, and doubtless there were some Fellows who, at the 
beginning of last year, regarded with no little apprehension the 
prospect of a revival of that controversy. But, notwithstanding the 
warmth with which it was debated in its new form, no one will, I 
am sure, deny the very great value that the renewal of the discussion 
—between Mr. Crisp and Mr. Shadbolt—has been in bringing to the 
light what had previously been confined to a few. If any one does 
not now comprehend how an immersion objective can have an 
aperture greater than that of a dry objective of 180°, at least it 
cannot be any longer charged against this Society, that means have 
not been provided to enable him to do so. 

The essential difference between the old and the new view of 
aperture is simply, that the former considered only the rays which 
enter the objective, while the latter deals with those which emerge 
from it. 

The disadvantage of the former method, which estimated the 
incident pencils entirely by their angles, has been its inevitable 
tendency to give a fictitious importance to the angle of the entering 


150 Transactions of the Society. 


pencil, which was supposed to have a special virtue of itself, in the 
delineation of objects. Naturally, therefore, the same angles, whether 
in air or any immersion fluid, were considered to produce an equal 
effect, and the advantage of immersion objectives was rested on 
minor points. 

An estimation of the emergent beam, however, must obviously 
give the same result as one of the incident beam (assuming them 
both to be correctly made), it being of course impossible for any- 
thing to emerge that has not first been admitted. But to quote 
Mr. Crisp :—‘ ‘The great and obvious advantage in dealing with the 
emergent pencil is that it is always in air, and so the perplexities 
are eliminated which have enveloped the consideration of the 
admitted pencil, which may be in air, water, oil, or other substances 
of various refractive indices.” * 

The subject of aperture is not, in reality, a difficult one, and any 
intricacy in which it may seem to be involved will be found to arise 
from the necessity of clearing away some of the old entanglements, 
such as the curious mistake involved in the ‘ hemisphere puzzle ” 
and similar matters. Looked at de novo, there are two simple 
stages in the aperture question. 

(1) To appreciate that, in using the term “ aperture,” we use it 
not in any artificial sense, but as meaning opening and nothing 
else,—defining, simply, the capacity of an objective for receiving rays 
from the object and transmitting them to the image. 

(2) That the aperture (as so defined) of an objective is determined 
by the ratio between the diameter of the emergent beam and the 
focal length of the objective. According as this ratio is greater or 
less, so the objective will receive and transmit a larger or smaller 
portion of the total quantity of rays presented to it. 

The emergent beam of an air objective of 180° angle cannot 
exceed in diameter twice the focal length; that of a similar water- 
immersion objective may be one-third larger, and of an oil-immer- 
sion half as large again, and the relative capacities of such objectives 
(with equal angles) to receive and transmit rays will always be as 
1, 14 and 1}. 

It cannot be too carefully borne in mind that it is not a question 
of this or that theory, but the ordinary laws of geometrical optics 
which determine that, all other things being equal, one objective 
will receive and transmit a greater quantity of light than another, 


* As pointed out by Mr. J. Mayall, jun., at the commencement of the dis- 
cussion, if 180° in air is equivalent to 82° in glass, the 140° in glass of the 
immersion lens must represent something more. This fact is, however, so con- 
stantly misinterpreted, owing to the supposition that when the immersion fluid is 
introduced the effect is only that the 82° is no longer compressed by the action of 
the plane surface of the lens, but is allowed to expand to 140°. This is one 
only of the apparent difficulties that obscure the proper estimation of the incident 
pencil, and which are avoided by dealing with the emergent beam. 


The President's Address. By Prof. P. Martin Duncan. 151 


and therefore has the larger or smaller aperture, according as the 
diameter of the beam emerging from it is greater or smaller. 

As Fellows of this Society we may, I think, be proud of the able 
communications, relating to this subject, which were published last 
year in the April and June numbers of the Journal. 


Numerical Aperture. 


The abandonment of the angular notation for aperture neces- 
sarily follows, as soon as the correct view of aperture is appreciated ; 
for when we know that the apertures of three objectives. are, for 
instance, as 98, 126, and 138, no one would insist that they should be 
designated 157°, 142°, and 130°. A notation can have no title to 
be considered a scientific one, which denotes things as the same 
when they are really different (60° in air and oil) or different when 
they are the same (180° in air and 82° in oil). 

Until, however, the “law of aplanatic convergence” had been 
demonstrated by Professor Abbe, no principle had been established 
by which the ratio between emergent beam and focal length, could 
be conveniently denoted. 

It would not be possible for me to condense, without a sacrifice 
of intelligibility, the steps by which he subsequently showed, in a 
very beautiful manner, that the ratio in question can be expressed 
by the product of the refractive index of the medium in front of the 
objective, and the sine of half the angle of aperture, that is by 
” sin u. 

Taking for our wnit the capacity of an objective for collecting 
the whole hemisphere of rays from an object in air (i.e. the case of 
a dry objective of 180° angle) we obtain the “ numerical ” notation, 
which commencing with the lowest numbers advances as far as 1°52 
with oil-immersion objectives, and by the use of which not only are 
apertures compared in the same medium, but in different media also, 
and we see whether they are smaller or larger than the maximum 
of a dry objective. 

It is gratifying to find that the reproach hitherto attaching to 
microscopists, for the use of a misleading notation, is, thanks to the 
efforts of this Society, being rapidly removed, and that the initials 
N.A. are no longer so mystic a symbol as they have been. I under- 
stand that many of the opticians have decided to use the numerical 
notation in the future issues of their catalogues, which is a step in 
the right direction, which we shall hope to see generally followed. 

Whilst on this subject I may point out how important it is 
that in observations with high-power objectives, their aperture as 
well as magnifying power should be stated. Whether a large or 
a small aperture has been used, may make a very material diffe- 
rece in the value to be attached to the results described. 


152 Transactions of the Society. 


The “ Homogeneous Immersion” principle. 


The utility of homogeneous-immersion objectives being estab- 
lished beyond doubt by practical experience, it 1s interesting to note 
that the origin of the principle is very fully recognized by Professor 
Abbe to be due to our esteemed Fellow Mr. J. W. Stephenson. 

‘he two essential points in homogeneous immersion are, Ist, 
the increase in aperture obtained by the use of a fluid of high 
refractive index and, 2nd, the enhanced optical performance arising 
from the total suppression of spherical aberration in front of the 
objective. Professor Abbe states that although Amici first applied 
oil immersion, he failed to recognize the specific advantage of an 
immersion fluid being as near as possible in refractive and dis- 
persive powers to the crown glass (i.e. “homogeneous”). He 
finished his lenses and then sought for oils and mixtures of oils of 
various refractive powers for obtaining the best correction. “ It 
was Mr. Stephenson who, in his first communications with me, 
expressed the opinion that doing away with the anterior aberration 
would improve the defining power, and especially would afford very 
favourable conditions for further increase of aperture.” 

The importance of this system will be appreciated when we 
remember, in regard to the first point (the increase of aperture), 
that the theoretical resolving power of an objective is thereby raised 
from 96,400 lines to an inch, which is the maximum of a dry 
objective, to 146,528 the maximum of an oil-immersion objective, 
the illuminating power being also increased from 1 to 2°25: while 
as regards the second point, we are able by the homogeneous-im- 
mersion method to reduce the problem of correcting a very wide- 
angled objective to the much less difficult one of correcting an 
objective of moderate air angle. Our lamented President, the 
Rey. J. B. Reade, declared in 1870 that “the ghost of aberration 
will never be entirely exorcised even by cold water.” But there 
appears to be good ground for believing that oil has practically 
accomplished that object. 

During the past year several kinds of fluids for homogeneous 
immersion have been brought before the Society, such as chloral 
hydrate and glycerine, iodide of zine and glycerine, and gum 
dammar and cedar-oil. Two other vegetable products have also 
reached us, “tacamaque” and the gum-resin “ oliban,” or “in- 
cense,’ both dissolved in cedar-oil. While the dammar is claimed 
to be unchangeable, and to be in refractive and dispersive powers 
very near that ideal of a good immersion medium, “ fluid crown 
glass,” there is evidently room for further research in this direction, 
particularly for a fluid which will not attack the various varnishes 
In ordinary use. 

Lastly must be noted an important advance in practical manu- 


The Presidents Address. By Prof. P. Martin Duncan. 153 


facture by the construction, by Messrs. Powell and Lealand, of a 
homogeneous-immersion objective of the large aperture of 1°47 
N.A. out of a possible 1°52. As long ago as 1850 one of my 
predecessors in this chair, expressed the belief that objectives had 
then “nearly, if not quite, attained the limit of perfection,” and 
whilst it will be prudent even at this much later date to avoid any 
assertion of finality in the present, or scepticism as to the possi- 
bilities of the future, it must be admitted that so far as regards 
aperture and resolving power we have arrived at a point beyond 
which it will, to all appearances, be difficult to advance, at any 
rate not without serious restrictions in the use of the objectives. 
Whilst it might be possible to work front lenses for objectives out of 
diamond, and so to increase the aperture to 2°5 N.A., and the 
resolving power to 241,000 lines to the inch, it must be remembered 
that it would be essential at the same time to provide an immersion 
fluid, slides, cover-glasses, and illuminators of the same refractive 
index as diamond also. 


Penetrating Power of Objectives—Depth of Vision. 


This again is a subject which has long been obscure; very - 
various opinions being held as to the true nature of what has been 
generally termed the “ penetrating power” of an objective. By 
some it has been declared to be a defect in the construction of the 
- objective—residual uncorrected spherical aberration, in fact; and 
by others as necessarily inconsistent with perfect definition, even 
with the best methods of construction; the only approximately 
correct notion regarding it, being that it decreased as the angle of 
aperture increased. 

Professor Abbe, however, in a very valuable paper, placed the 
question on the scientific basis so long needed, showing that the 
total depth of vision in the Microscope, i.e. the solid space which 
at one focus of the Microscope is visible with sufficient distinctness, 
depends not merely on the depth of focus of the objective, but is 
the sum of that and the depth of accommodation by the eye. 

The depth of focus (other conditions remaining the same) 
varies in inverse ratio to the magnifying power and also to the 
numerical aperture of the objective. Thus with a j-inch and 
4-inch of the same aperture the depth of focus of the former would 
be twice that of the latter, or if the powers are the same but the 
apertures are -50 N.A. and 1°50 N.A., it would be as 2 to -66. 

The depth of accommodation depends upon a point which was 
entirely new to microscopists until developed by Professor Abbe, 
viz. the peculiar property of microscopical amplification, by virtue 
of which the linear amplification of the depth of an object is 
largely exaggerated, being equal to the square of the linear 


154 Transactions of the Society. 


amplification laterally. Thus an object magnified, according to 
ordinary parlance, 100 linear diameters (i.e. in breadth) is 
magnified 10,000 linear diameters in depth. Now the depth of 
accommodation varies in inverse ratio to this depth-amplification, 
that is inversely to the square of the magnifying power, so that 
whilst large with the low powers, it decreases very rapidly and 
disproportionately as the power is increased. 

The joint effect, therefore, of the diminution in the depth of 
focus and depth of accommodation is that the total depth of 
microscopical vision diminishes, not in the same ratio as the increase 
in the magnifying power, but at first in a much greater ratio. 
With the low powers we have considerable depth of vision, as it 1s 
then chiefly influenced by the large accommodation-depth. As we 
proceed to the medium powers (100-300) the accommodation-depth 
very rapidly diminishes, and becomes equal to that of the small 
depth of focus, so that the total depth of vision is necessarily small 
also. As the power is further increased, the accommodation-depth 
ceases to have any influence, and the depth of vision becomes 
principally depth of focus only. If, for instance, an amplification 
of 30 times is increased to 300, the depth is reduced not to 
ys but to only 4 of its original amount; or taking the depth of 
vision with a power of 10 times to be 2 mm., with powers of 
30, 100, 300, 1000, and 3000, it is only °254, -0273, °0047, 
*00094, and -00026 mm. 

The formula 

Depth of vision = n i= A+ 52) 
shows at once how much the depth of vision may vary by a change 
in the conditions—represented by the various factors in the formula 
—which make up the total effect, important among which, as will 
be seen from the form of the equation, is the refractive index n of 
the medium in which the object is mounted. 


Micro-Stereoscopic Vision. 


The determination of the depth of vision (in monocular ob- 
servation) naturally throws great light also on the conditions for 
effective micro-stereoscopic vision. It is obviously only when an 
object can be completely seen in all three dimensions at one adjust- 
ment of the focus, that a true stereoscopic image of it can be 
obtained. So long as only a single layer of inappreciable depth is 
visible simultaneously with any distinctness, no stereoscopic appa- 
ratus, however perfect, can- bring into view the form of the whole 
of the object. 

Now with low powers we have large visual depth, so that objects 
of considerable thickness can be seen as solids. By reason, however, 


The President's Address. By Prof. P. Martin Duncan. 155 


of the rapid decrease of the depth of vision to which I have re- 
ferred, the thickness of the objects which can be seen in relief, 
rapidly and disproportionately decreases as the power is increased, 
so that only very thin objects are suitable with even the medium 
powers, the absolute depth, in the case of an object magnified 300 
times, not amounting to a hundredth of a millimetre. With still 
higher powers the images of solid objects (though the decrease in 
depth is no longer so irregular) necessarily approach more and more 
to simple plane sections, the absolute depth with a power of 1000 
times amounting only to a micro-millimetre. For medium and 
high powers, therefore, the only objects suitable for the stereoscopic 
binocular, are those which present, within a small depth, a sufficiently 

characteristic structure, that is, which have sufficient salient points 
for stereoscopic effect. We can, however, increase the depth of 
vision by using narrow illuminating pencils, and by mounting 
the objects in some highly refractive substance. ‘The above con- 
siderations also show the importance of using the lowest power 
sufficient to recognize the object. 

Whilst the reduction in depth limits effective stereoscopic 
observation, Professor Abbe properly points out that there is a 
compensating advantage in ordinary microscopic observation, in 
that as the depth-perspective becomes more flattened the images 
of different planes stand out from each other with still greater 
distinctness, so that ‘‘ with an increase of amplification the Microscope 
acquires more and more the property of an optical microtome, which 
presents to the observer's eye, sections of the object of a fineness and 
sharpness that no instrument could produce by mechanical means.” 

Another novel point was the demonstration of the very material 
distinction between ordinary stereoscopic vision and that with the 
Microscope. The perspective shortening of the lines and surfaces 
by oblique projection, which is an important element of solid vision 
with the naked eye, is wholly wanting in microscopical vision, in 
which we have only the other element, a relative displacement of 
successive layers in the image. That these displacements are seen 
in the Microscope, depends entirely on the peculiar exaggeration in 
the amplification of the depth of an object which is not found in 
ordinary vision. 

The paper “On the Conditions of Orthoscopic and Pseudoscopic 
Effects in the Binocular Microscope” is also a most useful contribu- 
tion to the theory of micro-stereoscopic vision, establishing as it 
does the true criteria for both classes of effects, and at the same 
time clearing up a misconception that had arisen as to the supposed 
necessity for the rays from the two halves of the objective crossing 
in order to get proper orthoscopic effect. If the delineating pencils 
have been reflected an even number of times in the same plane, the 
rays must cross, but otherwise not. 


156 Transactions of the Society. 


Mounting-Media of High Refractive Indices. 


To utilize the full benefit of immersion objectives, it is of course 
essential that the object should be mounted in a medium, the 
refractive index of which is not less than that of the immersion 
fluid ; and down to a comparatively recent period Canada balsam 
was most commonly used for this purpose, particularly for 
diatoms. 

Mr. Stephenson, however, pointed out that although by the 
use of the balsam we have attained our object so far as the aperture 
is concerned, yet we have done so at the expense of the visi- 
bility of the resultant image, which has become fainter by the 
nearer approximation to equality of the refractive indices of the 
diatomaceous silex and the balsam ; the visibility of minute struc- 
tures being proportional to the difference between the refractive 
indices of the object and the medium in which it is mounted. 
Instead of balsam, therefore, media of high refractive index should 
be employed ; thus, as the refractive indices of diatomaceous silex and 
Canada balsam are respectively 1:43 and 1°54, the difference *11 
is the measure of the visibility of a diatom in balsam. Using a 
solution of phosphorus in bisulphide of carbon, the refractive dex 
of which is 2°10, the difference is ‘67, and the visibility of the 
diatoms is now more than six times as great as it was in the 
balsam. 

Continuing his researches on this subject, and endeavouring to 
find the best media with high refractive indices, he has quite lately 
brought before the Society the utility of an aqueous fluid capable 
of being given the high refractive index of 1°68, viz. a solution 
of biniodide of mercury and iodide of potassium in distilled water. 
This more manageable and highly antiseptic medium appears 
likely to turn out to be of great use in the observation of many 
objects, as its strength can be diluted till the index of water is 
obtained. This is of advantage with such objects as muscular fibre, 
which are themselves of high refractive power, so that fluids of 
low refractive power must be made use of to obtain the required 
difference for more perfect visibility. The same communication 
also contains what was much wanted, detailed practical directions 
for mounting. 

Any one who has seen the diatoms and scales mounted in phos- 
phorus by Mr. Stephenson’s method, and exhibited at our meetings 
during the past and present sessions, cannot fail to have been 
struck by the great increase in their visibility as compared with 
those mounted in balsam, or to have recognized the fact, that the 
theoretical consideration by which their visibility was pronounced 
to be much increased, was not unfounded. 

In addition to the increase in visibility, there is also the fact 


The President's Address. By Prof. P. Martin Duncan. 157 


that by means of such mounting fluids, the capacity of stereoscopic 
binoculars with the higher powers is considerably enhanced. ‘True 
stereoscopic effect, as we have seen, requires a depth of vision 
not less than the thickness of the object under observation — a 
depth which, as already shown, increases in direct proportion with 
the increase in the refractive index (n) of the mounting fluid. 
If one object is in air when » = 1:0, whilst another is in a 
solution of phosphorus, where n = 2°1, the depth of vision will 
be more than doubled. Objects, therefore, that by reason of their 
thickness could only afford an unsatisfactory stereoscopic effect in 
air may be seen in tull relief when mounted in phosphorus. 

Here, again, the deductions of theory were remarkably verified 
_ by the recent exhibition of Surtrella gemma, under the binocular, 
with a ;!;-inch objective. 


Relative Value of Objectives with Large and Small Apertures. 
(“ All-round Vision ’’). 


T now come toa much-vexed question, that of the relative value, 
practically, of objectives of large and small apertures, in regard to 
which a great variety of opinions have been promulgated. 

The oldest of these views was that which made the preference 
between the two kinds of objectives, depend upon whether they 
were to be used for the “ordinary purposes of the biologist,” or 
for the examination of diatoms or other lined objects. The objection 
to this view is, that it assumes the only function of a large aperture 
to be its resolving power, a much too restricted notion, and one 
which deprives the working biologist of a most essential aid to his 
observations upon structure. 

A more modern view errs in the opposite direction, and insists 
upon the universal superiority of large apertures, so that work 
done with small apertures will “ have to be done over again.” 

There is again a third view, still more recently put forward, 
which goes much further than the preceding, and according 
to which it, is impossible that wide apertures can give correct 
images. First on account of the unnatural ‘all-round vision” which 
it is contended is obtained with them, and secondly by reason of 
their supposed inherent defect in defining power, in consequence of 
the dissimilar images presented by the different parts of the 
enlarged area of the objective, with a confused image as the general 
resultant. 

The want of exactness in the first two suggestions will suffi- 
ciently appear, when we have formulated the grounds upon which 
large apertures are shown to be indispensable for all observations 
upon minute structure for which high powers are necessary ; but it 
will be desirable first to point out the erroneous interpretations upon 


158 Transactions of the Society. 


which the third view (as to all-round vision and dissimilar images) 
has been founded, and for this purpose it will be necessary to refer 
to the paper by Dr. Royston-Pigott, F.R.S., in which the subject is 
dealt with.* 

After reminding his readers that he had shown that spider- 
lines, miniatured down to the fourteenth part of the hundred- 
thousandth of an inch, were distinetly visible to ordinary good 
eye-sight under proper microscopical manipulation (an experiment 
which, I may remark in passing, has not a satisfactory foundation), 
Dr. Pigott says:—‘‘ Under these circumstances it was interesting 
to know whether real objects could be detected by the Microscope 
in the surprising degree of attenuation represented by the mil- 
honth.” Muinute particles of mercury were obtained by smashing 
some with a watch-spring, and they were mounted in petroleum 
under a thin cover. A vertical illuminator was used to converge 
rays downwards, through the objective, upon the preparation. In 
a darkened room minute disks became visible, and upon some of 
them clusters of minute black points were seen with a power of 1000 
diameters. Comparing them with a micrometer spider-line +5355 
inch diameter, some of the points were found to be decidedly 
smaller. Under 1000 diameters the particle was magnified one 
hundred times in the micrometric focus, and then appeared less 
than the spider-line. Its real diameter was therefore less than 
roo Of todoo inch, or less than the millionth of an inch, and 
the writer draws the conclusion that “ real objects of unsuspected 
minuteness may be microscopically displayed as well as minute 
miniature images.” ‘To this part of Dr. Pigott’s observations it 
may be pointed out that it has never been supposed, so far as I am 
aware, that there is any limit of visibility in the Microscope other 
than that imposed by the sensibility of the observer’s retina, the 
correction of the objective, and the illumination. The question of 
a limit of visibility is quite distinct from that of a limit of separation, 
just as in telescopic vision a single star is always visible, however 
small its visual angle, provided it is sufficiently bright, but a double- 
star requires a certain minimum aperture of the objective, dependent 
on the angular distance of both stars. 

Discussing the variability of the blackness and thickness of the 
marginal annulus of refracting molecules, as exemplified in a glass - 
spherule ‘1 inch diameter, and in the featherlets of the death’s- 
head moth and plumelets of Hipparchus Janira with objectives of 
20° Ang. Ap. power 200, and 140° Ang. Ap. power 800, he 
writes :—* If then the minute fibrillee of the plume can be clearly 
distinguished as closely packed black lines at a visual angle of 
20 seconds with a low aperture of 20°, this result is fatally opposed 
to the popular idea that very close lines, or very minute lines or 
bodies, can only be distinguished with large angular aperture. 

* Proc. Roy. Soc., xxxi. (1881) pp. 260-78, 


The President's Address. By Prof. P. Martin Duncan. 159 
These lines were most sharply seen though less than ¢5}55 inch 
thick.” After noting the disappearance of distinctive shadows and 
consequent obliteration of structural molecules with excessive 
angular aperture, illustrating his meaning by the structure of 
Podura scales, with different stops and under very varying condi- 
tions, Dr. Pigott states that he has come to the conclusion that 
residuary aberration was not the only cause of the obstinate 
obscuration of minute crowded molecules in translucent organic 
forms, but that 

“ Excessive angular aperture, he found, attenuated mar- 
gin. ... There is, it may be said, something unnatural 
in the mode of vision intrinsic to very high angled glasses. It 
is undoubtedly true that such a glass presents an all-round 
vision. It really conveys visual rays from a given brilliant 
particle, at every inclination in azimuth and altitude, and 
this too at one and the same instant. To illustrate this 
position a minute die may be imagined the ,5,;5 inch 
broad. The highest angled objective really enables the 
observer to collect rays emanating from four szdes and the 
top at the same instant. The human eye could at most 
view three sides at once. Doubtless the effect of this 
angular vision all round the corners, causes particles to look 
spherical, when sufficiently minute, even if cubical.” 

Now it is necessary to say plainly that this view is founded 
upon a fundamental error, “belonging,” to use Professor Abbe’s 
words, “ to the venerable relics of the past naive period of micro- 
scopical science, which was characterized by an unshaken conviction 
in the validity of the hypothesis that microscopical vision is in all 
essential respects the same thing as ordinary vision.” The “all- 
round vision,” by virtue of which we are supposed, when looking at 
a minute cube, to see at the same time the top and all the sides 
(with the result of rounding off the corners and angles !), does 
not really exist, as can be shown by the application of the simplest 
laws of geometrical image formation. ‘The different obliquities of 
the rays in an objective of wide aperture cannot give rise to any 
all-round vision, for in the Microscope there is no difference of 
perspective attendant upon oblique vision as with the naked eye. 
The difference of projection of successive layers which exists is 
ineffective, except in the case of binocular vision. This absence 
of perspective may be readily established by examining an object 
alternately by an axial and an oblique ray ; it will be found that there 
is no shortening of the lines in the latter case, and no capacity 
in the Microscope, therefore, for “all-round vision.” Indeed if 
this theory were correct, microscopical vision, even of plane objects 
and with very moderate apertures, would be entirely destroyed. 

Equally mistaken is the second branch of the view which I 
am considering, viz. that a wide aperture must, in the nature of 


160 Transactions of the Society. 


things, impair definition on account of the increase, thereby pro- 
duced, in the dissimilar images received through the several parts 
of the objective. In support of this view, illustrations drawn 
from stereoscopic vision are adduced, which admittedly does 
depend upon the dissimilar images formed by the right and left 
hand halves of the objective; but, as Professor Abbe has shown, 
the dissimilarity of images presented by an objective of wide 
aperture is a dissimilarity in the projection of successive layers 
only, and this is not effective unless we produce these images by 
different portions of the aperture separately and conduct them to 
different eyes, as in binocular Microscopes. The sole effect of the 
wider aperture when the images are not so separated, is a reduction 
in the depth of vision—to confine us to the vision of thinner objects, 
not to impair the definition of what is seen when the objects are 
within the range of penetration. 

If we pass to practical experience, we shall find that the 
principles which theory establishes are amply confirmed. All 
who have worked with wide-angled objectives cannot fail to have 
recognized the great fact of modern practical optics, the perfection 
of definition obtained with such glasses—a fact which has been 
verified by such authorities as Mr. Dallinger, who, so long ago as 
1878, stated of a new 1-inch homogeneous-immersion objective of 
the wide aperture of 1°25 that ‘the sharpness and brilliancy of 
the definition which this lens yields is absolutely unsurpassed in 
my experience.” 

The question of the power of resolution supposed to be pos- 
sessed by small apertures can also be brought to a very simple 
practical test by those who believe in that view exhibiting here to 
the appreciative assemblage which they would have around them, 
say 75,000 lines to an inch resolved with the low apertures 
referred to ! 

We have seen that on the one hand the depth of vision 
decreases as the aperture is increased, and that on the other as the 
objects become smaller and smaller the similarity of their images 
increases with the increase in the aperture—the one representing a 
disadvantage attendant upon large aperture and the other an 
advantage—and bearing this in mind we are in a position to arrive 
at a cdrrect view of the relative value of objectives with large and 
small apertures, which I take to be this :— 

Both kinds of objectives are necessary for investigations into 
the structure of minute objects, and an observer to be fully 
equipped, should provide himself with two objectives, one of 
moderate and one of wide aperture. The former would be 
used for the more general survey of the various parts of the 
object, and the latter for the subsequent examination of its minute 
structure. In searching, for instance, through a stratum of fluid 


The President's Address. By Prof. P. Martin Duncan. 161 


for Bacteria a wide aperture would be unnecessary, but when a 
particular Bacterium is found, it is only that which will give us 
an accurate view of its flagellum. 

But again, in the choice of the objectives, the proper relation 
between magnifying power and aperture must be maintained. For 
work with low powers, it is useless to have large apertures. The 
structure of the objects for which such powers would be used is 
not sufficiently minute to require large apertures for their proper 
delineation, and we therefore expose ourselves to the disadvantage 
of very restricted penetration and the trouble of delicate mani- 
pulation, without any corresponding benefit. 

On the other hand, it is equally useless to work with high 
powers (that is upon minute objects) with small apertures. We 
should have only an empty amplification—mere imcrease in the 
distance apart of the outlines, without any additional structure 
being made visible in consequence of the defect in aperture. 

Whenever the subjects of our examination are so minute as to 
require high amplifications in order to be seen, then we must 
also have large apertures in order to obtain perfect delineation of 
the objects. 


Leaving now the theoretical questions, which after all have so 
important a bearing on our practical work, reference only need be 
made to the descriptions published in our Journal of new inventions 
in regard to mechanical and optical appliances (most of which 
have been exhibited at our meetings) to prove that great progress 
is being made in the designing, manufacture, and application of the 
Microscope. Improved stands and eye-pieces, new immersion lenses, 
stages, and swinging substages, more effective fine movements and 
elaborate accessory apparatus of all kinds, indicate not only the 
activity of mind and the abundance of the resources of the micro- 
scopical optician, but that these things are really required in a 
progressive science. 

It is to be hoped that the possession of excellent instruments 
and convenient apparatus will incite many of the Fellows to under- 
take more careful researches into the minute details of organic 
nature, or amongst the very fascinating rocks which are being so 
beautifully cut and mounted by petrologists. It is true that the 
difficulty of getting upon a path of original research is very 
deterrent. The activity of Continental and American microscopists 
is indeed great, and it 1s always necessary, before committing one- 
self to any statement, to search and prove its originality. Much 
microscopical research is quite beyond the powers of the man who 
has other avocations, and to whom the instrument is a pleasing, 
and none the less important, toy. Consider the paraphernalia 
required to study the microscopy of the details of a minute animal. 

Ser. 2.—Vot. IT. M 


162 Transactions of the Society. 


It has to be put into hardening and water-absorbing solutions, 
then to be cut with microtomes, perhaps frozen in the first instance, 
then to be put into other solutions to be cleared and to have its fat 
got rid of, and then it has to be coloured once, twice, or thrice, and 
possibly to have some colour discharged.. F'inally it has to be 
mounted in a medium. It is necessarily somewhat deterrent for a 
modest microscopist to read the excessively pronounced opinions of 
manipulators, about the nature of the structure they discover in 
such complicated and altered organic matter, and to find that very 
contradictory opinions are published by different investigators about 
the nature of identical structures which have been differently 
prepared. It appears to many an amateur, who happens to in- 
vestigate structures by disturbing their natural condition as little 
as is possible, that he is, as it were, out of the field. He may find it 
necessary, even in examining the simplest section, to pay especial care 
to the illumination and centering, and to the application of particular 
powers. He is, of course, conscious of inferiority, when he knows 
that somebody merely puts a chemically treated specimen under an 
objective without the least care about optics, and finds out, or 
thinks he finds out, the truth. But there are numerous oppor- 
tunities for original research still to be met with in the structure 
of many of the commonest invertebrates and plants. The study 
of rocks is in its infancy, and there are many very interesting 
physical questions yet to be determined, and which can only be 
settled microscopically. Recondite manipulation is not much 
required in any of these researches, but rather a good knowledge 
of how to use the Microscope as an instrument. 

If in any case there are obstacles to original research, it is 
always interesting to follow the work of some distinguished in- 
vestigator. It is very rarely that a subject is treated exhaustively, 
and the sedulous yet candid critic, may solve truths which his 
predecessor had not approached. 

In concluding this address, I cannot avoid a special mention of 
the recent death of a man whose genius and careful microscopical 
work, established an era in histology, and influenced that study of 
embryology which must ever be the starting point of philosophical 
zoology and botany. ‘Theodore Schwann elaborated the “cell 
theory” forty-three years ago, and in the main it holds good at the 
present day. He lived to see its value appreciated by every zoologist, 
and to be able to follow the researches with improved lenses, and to 
recognize the entities which have no cell-wall. Schwann investi- 
gated most successfully the nervous system, and his name will 
ever remain associated with it. He died at a ripe old age, having 
led an industrious, simple, and most useful life, and having lived to 
see himself the recipient, on the occasion of his jubilee, of distin- 
guished honours on the part of the scientific world. 


( 163 ) 


V.—On Mounting Olyjects in Phosphorus, and in a Solution of 
Biniodide of Mercury and Iodide of Potassium. By Joun 
Ware StrepHenson, Vice-President R.M.S., F.R.A.S. 


(Read 11th January, 1882.) 


In the use of modern objectives having numerical apertures ex- 
ceeding untty, or, in other words, exceeding the equivalent of 180° 
in air, it is absolutely essential, and this cannot be too strongly 
impressed, that the refractive index of the medium in which an 
object is mounted, shall at least equal the numerical aperture 
of the objective employed. 

~ Hence it follows that air, having a refractive index of 1, is not a 
suitable medium in which to examine an object under an objective 
of which the numerical aperture is more than 1, say 1-25, or 
1-47; the former being that of the first homogeneous immersion 
objective (made by Zeiss), and the latter that of the most recent 
production of Powell and Lealand. 

For instance, water, having an index of 1°333, is a medium of 
sufficient power to develope the full aperture of the objective of 
N.A.1-25; whilst Canada balsam, or any other medium having a 
refractive index exceeding 1°47, is necessary for the latter. 

An object is literally mounted in air, only if a film of air inter- 
vene between it and the thin glass cover. If it adhere to the 
cover, the effect is the same as if it were half in air and half in 
_ glass, and if the aperture of the objective exceed unity, its effective 


: < Hs that is to say, one-half of the 
excess of aperture beyond unity, is, under these particular circum- 
stances, entirely lost. 

The problem then is, in all cases, to find some medium fulfilling 
the before-mentioned conditions, but at the same time such, that 
the difference in the refractive indices of the object and medium 
shall form a sufficiently strong image to give distinct vision, but on 
the other hand not so great as to render the object opaque. 

In some preparations, however, the end in view is to render 
certain parts of the object very faintly visible, in order that other 
parts may become more visible by contrast. This is notably the 
case in preparations which have been injected or stained with some 
pigment, when colour alone is depended upon to depict the structure. 
We all know that such an object in spirit or water or alcohol 
is frequently too opaque for our purpose; the difference in the 
refractive mdices of the material to be examined and medium em- 
ployed is too great, and we, therefore, “clear the object,’ as it is 
called, by transferring it from pure spirit, with its low refractile 
mM 2 


aperture is reduced from a, to 


164 Transactions of the Society. 


power, to the higher one of oil of cloves, and finally into balsam ; 
by so doing we have placed the object in a medium approximately 
of the same index as itself, we have optically got rid of the unstained 
portions, leaving the coloured parts more distinctly visible. 
Muscular fibre is an illustration of the effect produced on the 
visibility of an object under these conditions. In water or glycerine 
(optically considered) it is well shown, because the difference of 
refractile power is sufficient to depict the structure and not so great 
as to obscure the view; but mounted in Canada balsam, in which 
the two indices are so much nearer equality (balsam being less than 
the muscular fibre), the image is so faint that we resort to polarized 
light, if it be necessary to examine it under such circumstances. 
This, however, is a digression from the original scope of my 
observations, which were rather directed to the question of 
mounting when modern objectives of large aperture are employed. 
I have pointed out that if an object adhere to the cover the 


Eich ; but if it be mounted on the 


glass slip it is, for the purpose of our investigation, in the worst 
possible condition, as the effective aperture is reduced to something 
less than the equivalent 180° in air—very little less, it may be 
perhaps, but still, if a film of air intervene, its available aperture 
cannot be quite up to this limit. 

If Nobert’s 19th band were ruled on the slide, instead of on 
the cover, or, what is the same thing, if the plate were turned over 
and covered with a thin glass, so that a film of air, however thin, 
intervened, no objective that has ever been made, or I may say 
ever will be made, would be capable of making the lines viszble. 

The result would be vastly different, however, if Nobert’s plate 
were mounted iz some medium giving a difference of index sufficient 
to render the rulings visible ; such a medium is a saturated solution 
of phosphorus in bisulphide of carbon; here the respective indices 
of the object and medium are, (if Nobert’s lines are ruled on 
crown glass), about 1°52 and 2-1; the difference between these 
gives a greater degree of visibility than that of a diatom in air, the 
difference of the former being 0°58, and of the latter about 0°43. 

So mounted, the resolving power on such rulings would be 
increased by more than 11 per cent. with the first homogeneous- 
immersion objective, and by more than 19 per cent. with Powell 
and Lealand’s more recent production, so that the 19th band by no 
means represents the attainable limit of resolution, if such rulings 
are suitably mounted. 

In mounting objects in phosphorus there are three points of 
vital importance :— 

1. The object must be absolutely dry, or if moistened, it must 
be with a substance soluble in bisulphide of carbon. 


utilized aperture is reduced to 


On Mounting Objects in Phosphorus. By J. W. Stephenson. 165 


2. The phosphorus must be introduced with the least possible 
exposure to the air, as phosphoric acid is otherwise very readily 
formed, and this ruins the preparation. 

3. The solution of phosphorus must be perfectly clear and 
bright. 

Of not much less importance is the necessity of having a vessel 
of water at hand, in order that the bibulous paper which has been 
used in the process, may be instantly submerged so as to prevent 
the danger of spontaneous combustion, and also to avoid the 
inhalation of fumes from the phosphorus which are prejudicial to 
health. 

In the preparation of the solution a 2-drachm bottle without 

any contraction for the neck is employed. A filter of bibulous 
paper is formed, accurately to fit the bottle by folding the paper 
down and around a small ruler or other cylinder of wood, of such a 
size, that with the paper around it, it may fit tightly into the bottle, 
to the bottom of which it is forced, and the wood withdrawn. The 
filter is now moistened with a few drops of bisulphide of carbon, all 
excess beyond that which is necessary for this purpose being 
dashed out, and a piece of stick phosphorus, as pure as possible, 
and say + or of an inch in length, dropped into the filter, and the 
bottle corked ; the vapour from the bisu!phide instantly acts upon 
the phosphorus, and in about half an hour or less it will be 
entirely dissolved, but still remaining in the filter. By taking a firm 
hold of the edge of the filter with a pair of forceps, and very 
slowly drawing it upwards, a partial vacuum is formed beneath the 
filter, and the pressure of the atmosphere on the surface of the 
solution forces the phosphorus through the paper, and the brilliant 
highly refracting fluid is seen at the bottom of the bottle. ‘The 
filter now withdrawn must be instantly plunged in water for reasons 
already given. 

The phosphorus being thus prepared, the mode of mounting 
is as follows. We will suppose the object to be diatoms, and of 
course adhering to the cover. 

In the first place a ring, somewhat smaller than the thin glass 
cover, is formed on the slide in the usual way, using for the 
purpose a solution made of glue, mixed with a small quantity of 
Hae which preparation when cold should form a somewhat stiff 
jelly. 

‘The thin cover is now placed on the glass slip, but being raised 
on one side by a piece of bristle or fine wire, it is only the opposite 
-side which touches the glutinous ring, to which it adheres. The 
reason for tilting the cover will be seen hereafter. 

The next step is the real mounting, which is effected by means 
of a pipette; this is made of glass tubing (say } of an inch in 
external diameter), drawn out to a fine point at one end, the other 


166 Transactions of the Society. 


more open end being capped with about an inch of indiarubber 
tubing, whipped on to make the joint air-tight, and the free end 
closed by a clump or plug or by any other means. 

The pipette thus made is passed through a cork, so that the 
fine opening formed at the pointed end shall reach the bottom of 
the bottle or nearly so, and will therefore be beneath the surface of 
the phosphorus. 

The indiarubber tube being squeezed, forces out some of the 
air contained in the pipette, and on relaxation of the pressure, the 
partial vacuum thus formed is occupied by a drop or perhaps two 
of the phosphorus. 

The fine point of the pipette, which will generally be found 
free from any adhering phosphorus, is now introduced beneath, or 
close to, the edge of the tilted cover. The tube is squeezed, and 
the phosphorus thus forced beneath the cover instantly fills up the 
space between it and the slide. It will not fail to be observed 
that the whole aim has been to expose the minimum surface of 
phosphorus to the oxygen of the atmosphere; if phosphoric acid is 
formed, either by fuming and condensation on the thin cover, or on 
the exposed surface of the phosphorus the object will, as previously 
stated, be spoilt. Should this operation have been successfully 
accomplished—and there is no difficulty in doing it—all risk is 
over ; the cover is gently pressed down and the mount closed by 
passing some of the warm preparation of glue around it. 

When this has set pretty securely, which will be in about half 
an hour, it will probably be found that some of the redundant 
phosphorus has escaped from beneath the cover; this is eon- 
veniently removed by a piece of blotting paper wetted with 
bisulphide of carbon; it must be applied with a pair of foreeps, 
special care being taken not to touch the paper so used with the 
fingers, and it must be plunged into water immediately after using, 
as it will otherwise take fire spontaneously, at ordinary tempera- 
tures, in the course of a minute or two. Phosphorus left in contact 
with glass does not appear to do this; at the same time it must 
not be forgotten that noxious fumes are always given off by 
phosphorus when exposed to the air, and it ought therefore to be 
removed. 

As it is possible, notwithstanding every precaution, that some 
phosphorus may accidentally get on the fingers, it is desirable to 
have a small quantity of olive oil, as well as an oiled rag close at 
hand. Phosphorus is very soluble in olive oil, and as the solution 
is incombustible (spontaneously) an instant application removes the 
danger. It may seem that this risk has been too much dwelt 
upon, but as a burn from phosphorus is frequently very severe, it 
does not appear to the writer to be inopportune to urge the point. 
The slides may now be put aside for a day or two, when they can be 


On Mounting Olyjects in Phosphorus. By J. W. Stephenson. 167 


finally completed by two or three successive coatings of gold size, 
after the first of which, any superfluous glue should be removed 
with water and a camel-hair brush, and “to make assurance 
doubly sure” a ring of sealing-wax (shellac) varnish after the last 
coating of gold size may well be added. 

The slides thus prepared appear to keep perfectly well, as one 
of P. formosum which I mounted nine years ago and exhibited 
here on the 4th June, 1873, still remains unchanged ; but it is fair 
to say, that having been during that period in my cabinet, it has 
had little exposure to daylight. 

In addition to the increase of visibility there is another point of 
interest in the use of phosphorus. It was pointed out by Professor 
Abbe in our last volume, pp. 689 and 832, that depth of vision 

2 

=) ae + oN from which formula it is obvious that the 
depth of vision (on which stereoscopic vision depends) increases in 
the same ratio as the refractive index (7) of the mounting medium. 
Hence it follows that the stereoscopic effect of phosphorus, with its 
index of 2°1, is more than double that of the same object mounted 
in air (n = 1), and it is to this circumstance that the stereoscopic 
appearance of the scales of Machilis maritimus and Tomocerus 
 plumbeus under a jj; is to a great extent due. 

There is now another fluid to which it is very desirable I should 
again draw attention, and that is a solution of biniodide of mercury 
and iodide of potassium in distilled water. This is very easily pre- 
pared by adding the two salts to the water until each shall be in 
excess; when this point of saturation has been reached the liquid 
will be found to have a refractive index of 1°68, by far the highest 
aqueous solution known to me. With this fluid there is no 
difficulty or danger (apart from its poisonous nature) whatever, 
either in mounting or preparing. Its advantages from an optical 
point of view are considerable, and it may be used of any strength : 
commencing with pure water, with a refractive index of 1°33, we 
can go on progressively to 1°465, which represents glycerine, still 
on to 1°54 (Canada balsam), again onwards to 1-624, which 
represents bisulphide of carbon, to 1°658 which represents the 
monobromide of naphthaline, to 1-662 the equivalent of a solution 
of sulphur in bisulphide of carbon, until, undiluted, it finally 
reaches its own maximum of 1°680;—thus we have the repre- 
sentatives of all these media and an infinite number of others in 
this one fluid. 

As mentioned at our last meeting, it is easily sealed with white 
wax, and I have found the following a simple and effective plan of 
doing so. 

The glass slip having been heated on the turntable, a wax cell 
is formed by touching its surface with a piece of white wax; in the 


168 Transactions of the Soczety. 


centre of the circle thus formed, when cold, a drop of the solution 
is placed, and on this the thin glass cover. 

The cover can be fixed by heating an ordinary gun-punch (or 
other metallic ring) to the melting-point of wax, and placing the 
cutting edge on its upper surface ; the weight of the punch as the 
wax melts soon adjusts the cover in its place, and when cold the 
excluded solution is cleaned off. 

Two or three coatings of gold size and one of shellac finally fix 
it, as in the case of the phosphorus. 

This fluid is so dense, its specific gravity being 3°02 (as kindly 
determined for me by Mr. C. G. Stewart, of St. homas’s Hospital), 
that almost any microscopic object will float on its surface; this is 
the case with diatoms, for example, and consequently any which 
may become detached will still be found in contact with the cover, 
and may thus possibly present themselves under different aspects. 

Its refractive index being 1°68, the visibility of diatoms, when 
mounted in it, is represented by the number 25 as compared with 
11 in Canada balsam—in other words the image is nearly 23 times 
as strong; this is no doubt very inferior to that yielded by 
phosphorus, in which the strength of the image is 6 times as great 
as in balsam, but nevertheless, Amphiplewra pellucida is very 
easily resolved in it, and on looking over a slide, mounted last 
evening, not one valve was found (and they were delicately marked), 
which was not resolved without any trouble under Zeiss’ homo- 
geneous 4. 

For muscular fibre, on the other hand, a strong solution is not 
suitable, since the high refractive power of the object approaches that 
of the medium, and the resulting image is consequently very faint, 
but as every other medium of a lower index than 1°68 can, by 
dilution, be represented by it, any degree of visibility down to that 
yielded by water can be obtained. 

For marine animals a weak solution is probably well adapted, as 
about a 1 per cent. solution (5 minims to the ounce) will give the 
specific gravity of sea-water, with no appreciable difference in the 
refractive index ; and the same strength appears suitable for some 
vegetables. How far the colours of these may fade can only be 
determined by time, but a limited experience shows that the colour- 
ing matter of the petals of flowers is dissolved out, although the 
action on chlorophyll appears in some cases to be small, after two 
or three weeks’ exposure. 

Although the dispersive power of a mounting medium is not of 
importance, it may be mentioned as a matter of interest, that the 
dispersive power of this fluid is excessively great, being equal to 
005483 (that of very dense flint glass, n = 1°802, being only 
0: 03287), and the extension of the blue in comparison with the 
red, much greater than that of any other known substance, as I am 


On Mounting Objects in Phosphorus. By J. W. Stephenson. 169 


informed by Professor Abbe, who kindly determined these points 
with his Refractometer from a sample sent by me for his 
examination. 

Being an aqueous and highly antiseptic fluid, no transfer from 
it to another medium is required, but I am unable to say what 
its effect may be on stained preparations, possibly unfavourable, 
but on this point as well as on its chemical effect on different 
structures I am unable to express an opinion at present. On the 
whole, however, I venture to think that for the above and other 
reasons it is destined to become of great importance in the micro- 
scopy of the future. 


170 Transactions of the Society. 


VI.—On the Threads of Spiders’ Webs. 
By Joun Antuony, M.D., F.R.M.S., &e. 
(Read 11th January, 1882.) 


In the course of observations on the habits of spiders, and more 
particularly of those which construct geometrical webs, an idea 
occurred, that by management, the Hpeira Diadema—one of the 
largest of our garden spiders—could be made to spin his thread in 
such a way, as to cause the whole, or the greater part of the strands 
composing this minute cord or cable, to remain separate, instead of 
coalescing, and so forming the well-known “thread ”’ by which the 
diadem garden spider is so often seen suspended. The experiment 
answered perfectly, and the results were so full of interest for the 
student of natural history, as to cause me to describe carefully the 
means I employed, so that any one may be able to repeat the expe- 
riment, and arrange fairly permanent preparations of the parts 
making up the spider’s thread for deliberate examination under the 
Microscope ; premising, that so far as is known, the same method 
will be equally successful with any of the web-spinning spiders. 

A fine Epeira Diadema, suspended as usual by his thread, 
being available, six ordinary slips of microscopic glass were placed 
in readiness to have the spider’s thread wound upon them as it was 
spun. The idea acted on was, that the threads issumg from the 
hundreds of “spinning-tubes” on the various papille or teats, 
known as “ spinnerets,” must travel for an appreciable distance ere 
they coalesced in a more or less hardened but still glutinous con- 
dition, to make up what we call in popular language “ the spider’s 
thread,” and that, therefore, these ultimate fibrils, though numbered 
by hundreds, and of exquisite fineness, could assuredly be intercepted 
at a point sufficiently near the spinnerets to cause the strands 
to remain -separate on the surface of the glass slip, instead of 
coalescing. The slip was then made to catch the Epeira thread, 
winding the line so as to come near the body of the spider, who not 
liking the look of things, lowered himself, as was expected, rapidly 
towards the ground to escape, and was as rapidly wound up, and 
raised into mid-air. 

Now, as spiders do not like to part with spinning material if 
they can avoid it, and as Epeira evidently got no nearer the ground, 
he paused in his “ paying out” of line to think a little, and he did 
not cut his thread, inasmuch as a fall from that height was not to 
be risked; so, as he was now pretty steady, another slip was brought 
into operation, the edge of it placed close under the spinnerets, or 
in the actual position of the spider, rather above them, and once . 
having got adhesion of these issuing strands while they were quite 
separate, it was manifest that with due precaution in winding up, 


On the Threads of Spiders’ Webs. 171 


the strands need not be allowed to approximate to form the rope ; 
so wind after wind, the exquisitely delicate floss-silk-like strands 
were stretched over the surface of the glass slip—evident to the 
naked eye by an iridescent appearance. ‘These strands being 
directly across the slip at right angles to its long axis, would be 
very close together, even if not often touching each other, so on 
another slip a variation was made, by tilting the slip sideways as it 
was turned to receive the strands; the brush of minute filaments, 
which had a tendency to approximate, was now made to diverge, 
and spread out on the surface of the slip into a sort of fan-shape, 
and this arrangement may be seen on the slide under the Micro- » 
scope. Irom the very small portion visible under a magnifying 
power, the effect is, that the minute filaments are parallel, like 
 harp-strings, to which they bear no small resemblance, but in- 
spection will show that this mass of filaments has by the device 
named been rendered divergent. 

There was now no difficulty in covering all the remaining slips 
with these separated components of the spider’s thread, and, as 
might be expected, these slips showed, on after examination under 
the Microscope, every variety of combination by which the infinitely 
small filaments combined to make up a manifestly substantial 
cable; so that, taking the number of teats bearing the ordinary 
spinning-tubes to be four, there would be seen the four strands 
making up the cable, and in another part the ultimate filaments of 
which these strands were composed. 

I am glad all these things can be shown on the slip under the 
Microscope ; they look exquisitely beautiful by any mode of lighting, 
but under dark-ground illumination, the effect of hundreds of silver 
wires of marvellous delicacy is charming beyond expression. 

It may be stated that at the end of the experiment, Epeira, 
whose patience had been rather severely taxed, was let down 
near to the ground, when, the haste with which he severed his 
thread and scampered off, was evidence that his quietude in mid- 
alr was more a matter of prudence than inclination. 

An identical mode of obtaining a division of the thread was 
employed in the case of a very small spider which has the habit of 
lowering itself from ceilings, the trivial name of which is “ Money 
Spider.” The results obtained were very similar, the thread was 
seen divided into its component parts, but how many parts it 
would be difficult to say, for the difficulty now became to find these 
ultimate filaments; it was evident that they were there, but so fine 
as to require a careful illumination and a fine high-power objective, 
with very careful touches of the “fine adjustment,” to make them 
out, and then they looked very much like very finely ruled micro- 
meter lines irregularly spaced. 

It is rather important to notice one portion of the conclusions 


172 Transactions of the Society. 


arrived at from these experiments, and that is, that in reckoning 
up the number of filaments spun by Diadema, and going to make 
up the cable, the count always came below 200. Now this would 
appear quite insufficient as a product of the spinning-tubes, which 
in a fine preparation I have of the spinnerets by Bourgogne, 
certainly exceed 1000 in number; so it would seem we have to 
fall back upon the conclusion, that either all the spinnerets are not 
in action at the same time, or, that a considerable proportion of the 
spinning-tubes, which have apparently some differences in structure, 
have also a different function to perform, such as cross lines of the 
geometric web and “bead globules.” This is mere surmise, but 
the fact of the small number of ultimate filaments in relation to 
spinning -tubes remains. 

A description of the mechanism of the spinning apparatus 
would make this paper too long. It would form the basis of a 
future communication, or the materials are at the service of any 
microscopist who wishes to work out the subject. 


(sn) 


SUMMARY 


OF CURRENT RESEARCHES RELATING TO 


LOOLOGY AND “BOTAN Y 


(principally Invertebrata and Cryptogamia), 


MICROSCOPY, &c., 


INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* 


ZOOLOGY. 


A. GENERAL, including Embryology and Histology 
of the Vertebrata. 


Germinal Layers and Early Development of the Mole.t—Mr. 
W. Heape gives the results of investigations upon the origin and 
formation of the germinal layers in mammals, more especially in the 
mole (Talpa Europea), as follows :— 

1. The epiblast of the blastodermie vesicle owes its origin as 
well to the inner mass of segmentation-spheres as to the outer layer 
of segments. It appears to originate in two ways :— 

a. In the early stages of development (in the mole), probably by 
the cells of the inner mass being directly transformed into part of the 
wall of the blastodermic vesicle. 

b. In a later stage (mole and rabbit), by the transformation of the 
rounded cells of the inner mass into a plate of columnar cells, which 
joins the part of the outer layer immediately above it to form the 
epiblast plate of the embryonic area. 

2. The mesoblast in the mole is formed in two portions :— 

a. A large portion, which has its origin in the primitive streak. 

b. A smaller portion, which is derived from the hypoblast situated 
in front of the primitive streak. 

The author was unable to distinguish where the latter, or hypo- 
blastic mesoblast, comes into contact with the mesoblast of the 
primitive streak, and what part these respective layers take in the 
future development of the embryo. 

3. A neurenteric canal is present in the mole similar to that formed 
in other types of Vertebrata, first appearing as a pit at the anterior 
end of the primitive streak, while in later stages it perforates the floor 
of the hinder end of the medullary groove. 


* The Society are not to be considered responsible for the.views of the 
authors of the papers referred to, nor for the manner in which those views 
may be expressed, the main object of this part of the Journal being to present a 
summary of the papers as actually published, so as to provide the Fellows with 
a guide to the additions made from time to time to the Library. Objections and 
corrections should therefore, for the most part, be addressed to the authors. 
(The Society are not intended to be denoted by the editorial ‘‘ we.” 

t Proc. Roy. Soc., xxxiii. (1881) pp. 190-8. 


174 SUMMARY OF CURRENT RESEARCHES RELATING TO 


He also found in a seven days’ rabbit embryo a rudimentary 
neurenteric canal, in the form of a shallow pit, in the epiblast at the 
front end of the primitive streak. 

4. The notochord is formed of an axial strip of cells, which under- 
lies the epiblast of the medullary groove, and which either never 
become divided into mesoblast and hypoblast, or in which such a 
division, if it does take place (as appears not impossible), is very soon 
lost. This strip of cells is originally continuous laterally with both 
mesoblast and hypoblast, but as the lateral mesoblast becomes con- 
verted into definite vertebral plates, the connection is lost. 

There can, it is believed, be no doubt of the connection of the 
lateral hypoblast and mesoblast with the notochordal cells in the 
mole; in the rabbit, Mr. Heape is inclined to believe that a similar 
connection is present, but his evidence on this point is not yet 
conclusive. 


Development of Amphioxus.*—In this paper Dr. B. Hatschek 
deals in detail with the earlier stages only. In describing his 
method of study, he says that he has always endeavoured to study 
in the living object all that it would allow. For the preservation of 
specimens in the cleavage stage Kleinenberg’s fluid was found useful ; 
and coloration was effected by osmic acid: the former was not 
adapted for the gastrula-stage, when osmic acid was used. The 
earlier stages of segmentation require a treatment different to the 
later, on account of the large amount of yolk then present; an addi- 
tion of 4 per cent. osmie acid to the sea-water killed the embryo in 
the earlier stages, when no colouring matter was employed; in the 
later stages Beale’s solution or picrocarmine were found useful. 

Oviposition is seen to be markedly dependent on the weather and 
the time of day; the generative products are most certainly expelled 
by the mouth. Development breaks up into two well-marked stages, 
the one embryonic, when it is effected at the cost of the nutrient 
material contained in the egg, and is veryrapid. At the close of this 
period the mouth is developed, and the first gill-cleft. The larva 
now begins to feed itself, its cells contain transparent protoplasm, and 
the developmental processes are very much slower. 

While giving a general support to Kowalevsky’s classical account 
of the earlier stages, the author finds that the ova are generally quite 
isolated. The five fat-bodies of the Russian author are regarded as 
yolk-granules ; the spermatozoa would appear to always enter at the 
vegetative pole. The cleavage was found to be unequal, the differences 
between the two poles being well marked. There is a pause of about 
an hour between the formation of the first and of the second groove. 

At the blastula-stage we find the investing cells taking on an 
epithelial character, till there is formed a general outer layer, enclosing 
a cavity. This simple epithelium forms the substratum for the later 
developmental processes; all the essential organs are formed by 
foldings or outgrowths from it. Bilateral symmetry is obvious at a 
very early period; the blastopore appears to close from before back- 


* Arbeit. Zool. Inst. Univ. Wien (Claus) iv. (1881) pp. 1-89 (9 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 175 


wards. The lower layer, which goes to form the endoderm, does not 
correspond to more than one-third of the blastula; this undergoes 
invagination, the fluid of the cleavage cavity becomes absorbed, and 
bilateral symmetry soon becomes well marked. 

In the “third period” the primitive segments, the nervous system, 
and the notochord begin to be apparent ; the remnant of the blastopore 
persists as an opening between the enteric cavity and the nerve-tube, 
representing the typical neuro-enteric canai. Contemporaneously 
with the development of the nerve-tube, the mesoderm developes the 
primitive segments ; two lateral longitudinal folds arise in the dorsal 
portion of the endoderm, and represent the rudiments of the mesoderm. 
The cavities of the primitive segments are diverticula from the 
archenteric cavity. 

After describing these points in detail, the author makes some 
_ observations on the mechanics of the developmental process. All 
those described are referable to foldings, solutions of continuity, 
or outgrowths. What are the causes of the first? Some are due 
to contractions of the protoplasm, to active changes of form, while 
others are referable to growth; in the others we have to note as an 
important factor differences in growth-energy. Active changes are 
limited to short periods, and the formation of the dorsal groove is an 
example; with this the development of the mesodermal folds has a 
close mechanical connection. Growth is more energetic in the 
anterior regions. The prime cause of the development of the meso- 
dermal folds would appear to be the greater superficial extension of 
the endoderm in the dorsal region; so, again, the formation of the 
first primitive segment commences by a flattening of the anteriorly 
placed endodermal cells; the cells pushed back are folded transversely, 
and so give rise to the first primitive segment. 

In the stage in which there are seven primitive segments there 
appear in front of them two dorsal folds of the endoderm; these 
become more and more marked, and give rise to two blind sacs, which 
are at first bilaterally symmetrical, and are placed at the anterior 
end of the enteric canal. About this time the epithelial cells become 
for the most part much more flattened; and the dissolution of the 
yolk-granules is almost completed. 

The fourth stage is the period of histological differentiation, 
muscles become apparent, the notochord undergoes histological 
differentiation, and fibrous cords appear in the medullary tube. At 
the same time the larva alters greatly in form, becomes elongated and 
compressed, and takes on generally a piscine character. The increase 
in the number of primitive segments goes on but slowly, but what are 
formed gradually fuse in the ventral median line. Each muscle-cell 
has at first only a single fibril, and there is no indication of segmenta- 
tion ; we may say, indeed, that a row of cells secretes a common fibril, 
which is continuous throughout the length of the body. The 
author cannot agree with Kowalevsky in thinking that there is any 
special chordal sheath, and he does not see here any difference from 
what obtains generally throughout the Vertebrata in the histological 
differentiation of the notochord; small vacuoles appear within its 


176 SUMMARY OF CURRENT RESEARCHES RELATING TO 


cells, grow in size and diminish in number, till at last they are 
so extensive that nothing but thin partitions intervene between 
them. 

The anterior endodermal sacs undergo development asymmetri- 
cally ; they become shut off from the exterior, the one on the right 
increases in size, while the left undergoes no change, till at the com- 
mencement of larval life it opens on the left side of the body by a 
small orifice. This is the special organ of larval life, as described by 
Kowalevsky. Another organ, the club-shaped gland, is also developed 
from the exterior. Formed in the region of the first metamere, it 
becomes towards the end of embryonic life shut off from the exterior. 
It now lies chiefly on the right side, but extends transversely across 
the enteric canal, and opens at the outer margin of the mouth ; part of 
it becomes glandular, and the rest forms an efferent duct. The 
external epithelium is still ciliated, but is now generally thinner, 

In the fifth period, the last here described, those changes occur 
which enable the embryo to pass into the larva. A number of orifices 
are now formed, the mouth and the first gill-cleft, the orifice of the 
ciliated organ (or left endodermal sac), the club-shaped gland, and 
the anus. The body meanwhile increases in length, fresh segments 
being formed, a number of strong motile flagella may be seen to be 
developed from the cells, and all the tissues of the body are now 
formed of transparent protoplasm. 


B. INVERTEBRATA. 


Fossil Organisms in Meteorites.*—In his own abstract of his 
detailed memoir on this subject, C. Vogt says, “I have endeavoured 
to discover whether the bodies to which Dr. O. Hahn calls attention,f 
really have the structural characters of the organisms to which he has 
assigned them. 

“ By a detailed comparison of the living and fossil sponges with 
the supposed sponges of meteorites, I am able to show that there is no 
resemblance in microscopical structure between them. I prove, by 
the same method, that neither the corals nor the Crinoids which 
Hahn believes that he has discovered in the meteorites have anything 
in their microscopic structure in common with living or fossil corals 
or Crinoids. I further refute the theory, which may be described as 
at least singular, according to which the corals are only an evolutional 
development of the sponges, and Crinoids a product of the further 
evolution of the corals. 

“JT demonstrate the fact that, in order to obtain the completest 
possible knowledge of the structure of the chondrites” (the species of 
meteorites from which the specimens were prepared) “ we must resort 
to check-experiments, based on dissociation of the constituent elements 
either by chemical reagents (as acids and caustic potash) or by the 
mechanical operation of grinding to the finest possible sections. The 
fragments which are obtained in this way should be studied by 


* Comptes Rendus, xciii. (1881) pp. 1166-8. 
+ See this Journal, i. (1881) pp. 722-4. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 177 


polarized and not merely by ordinary light. The check-experiments 
show with the greatest conclusiveness that the chondrites are entirely 
composed of crystalline pieces, vai ously disposed, and that organic 
structure is quite absent from them. 

‘“‘T then pass on to compare the structure found in the chondrites 
with those of artificial products which have been brought to the 
knowledge of the Academy by MM. Daubrée and Meunier. I prove, 
by camera drawings, that various crystalline forms which may be seen 
in meteorites were long since reproduced by M. Daubrée, and that 
the incrustations of enstatite made by M. Meunier exhibit under the 
Microscope the same radiating and jointed arrangement as the so-called 
organisms of Hahn. Finally, I demonstrate that the columnar for- 
mation which is only revealed by the use of the polariscope and 
by shaking, and which may be seen in certain chondrites, is also found 
- in rocks belonging to the globe under the same conditions. 

“ The comparative method of study which I have adopted, aided by 
drawings made from nature, leads me to the following conclusions :— 
(1) The alleged organisms of meteorites (chondrites) have no existence ; 
what have been described and figured as such are made up of crystalline 
bodies, entirely inorganic. (2) None of these alleged organisms have 
the microscopical structure which belongs to the real organisms with 
which they have been associated ; in particular, the so-called sponges 
do not exhibit the structure of the living or fossil sponges, nor the 
corals the structure of zoophytes or Anthozoa, nor the Crinoids that of 
the known forms of Crinoids. (3) The structure which has been 
observed is either due to the presence of an opaque encrusting substance, 
or is the result of optical illusions caused by an incomplete method 
of microscopical examination. (4) The study of thin sections, 
obtained by grinding, carried only up to a certain point, is insufficient 
to elucidate the structure of the chrondrites. This method of investi- 
gation must be controlled by observations made on sections reduced 
to an extreme degree of thinness, as well as by the examination 
of chondrites dissociated by acids and caustic potash. (5) The check- 
experiments show conclusively that all the chondrites are composed 
of transparent crystalline masses, grouped in different ways, but most 
usually in the form of miniature columns or ramified tufts radiating 
from a centre. The interstices, fracture-cavities, and gaps between 
these masses are filled with an opaque incrusting material, a con- 
siderable part of which resists the action of acids, and both simulates 
septa and has definite shape and other peculiarities which are attributed 
to organic structures. (6) The tufts which make up the chrondrites © 
are identical in their form and in the manner in which the crystalline 
pieces composing them are arranged, with the tufts of artificial enstatite, 
obtained by Meunier in his experiments ; just as the globular masses 
of crystals formed during the same experiments, are analogous in their 
manner of grouping to chondrites of ramifying and jointed structure. 
(7) In certain finely striated chondrites, a rectilinear columnar arrange- 
ment may be seen, identical with the structure of certain terrestrial 
enstatites (Schifferfels of Baste, in the Harz). (8) The greater number 
of chondrites contain a quantity of groups of enstatite crystals, identical 

Ser. 2.—Vot. II. N 


178 SUMMARY OF CURRENT RESEARCHES RELATING TO 


in their mode of grouping, their form, and structure with those ob- 
tained by M. Daubrée by fusing peridote with wrought iron (fer doua). 
(9) Deducting the pulverulent and metallic substances, and the un- 
crystallized encrusting materials, ordinary meteorites consist only of 
crystalline elements united to form chondrites; this is proved by 
disintegrating them by rubbing or by the use of acids. 


Red Pigment of Invertebrates (Tetronerythrine).* — At the 
coast it may readily be observed that a red coloration is very 
common among invertebrate animals, and even fishes. And accord- 
ing to C. Mereschkowsky, even the animals coloured yellow, brown, 
green, and black, have always a scarlet red pigment, which in their 
case is hidden by others. The red pigment, he finds, is always the 
same substance, viz. that known as tetronerythrine ; he has verified 
its presence in one hundred and four species (invertebrates and fishes). 
The question arises, what is the physiological réle of this widely 
expanded substance? The author finds evidence that it corresponds 
to hemoglobin in higher animals: serving for cutaneous respiration 
by virtue of its great affinity for oxygen. Thus, as regards distribu- 
tion in organs, wherever oxygen has to be largely consumed by the 
tissues, there tetronerythrine is abundant. This is illustrated by 
skin tissues in immediate contact with the oxygen of the water; by 
the organs of respiration (e. g. in sedentary Annelids the tetronery- 
thrine is concentrated in the branchie, the rest of the body having 
only traces); by muscles, and such an organ as the muscular foot of 
Lamellibranchiates. Next, as to distribution in the animal kingdom: 
sedentary animals are often redder, and have more tetronerythrine 
than errant animals; the latter which, by constant change of place, 
are always in water holding plenty of oxygen, not having the same 
need of a special substance to increase the oxygen absorbed by the 
tissues. Then the fact that tetronerythrine occurs by preference in 
invertebrates, where hemoglobin is wanting (and only exceptionally 
in higher animals), points to similarity of function in these sub- 
stances. It is further pointed out that animals provided with yellow 
cells (parasitic algze), which are proved to produce free oxygen in the 
tissues, are without tetronerythrine, or have very little of it. 


Mollusca. 


Maturation, Fecundation and Segmentation of Limax campestris. 
—In this remarkable contribution to embryology, E. L. Mark deals in 
the first sixty pages with his own observations ; the rest of the paper 
falls under the head of bibliography, and we have nearly three hundred 
pages devoted to a consideration first of the egg-envelopes and yolk 
of Limaxz, and secondly of a review of maturation, fecundation, and 
cell-division ; asters, quiescent nuclei, and nuclei in division are 
successively taken in review; and for the last, tissues as well as 
plants are examined ; the paper concludes with theoretical considera- 
tions and conclusions, in which attention is drawn to such important 
points as the promorphology of the ovum, asters, origin of nuclei, and 


* Comptes Rendus, xciii. (1881) pp. 1029-32; Nature, xxv. (1882) p. 276. 
+ Bull. Mus. Comp, Zool., vi., No. 12 (1881) pp. 173-625 (5 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 179 


polar globules, among others. An alphabetical bibliographical list, 
and a list of the authors cited in the text aids the reader in his study 
of the work. 

The eggs, usually found in clusters of about a dozen, vary in 
their mode of packing, and in their arrangement in the cracks of earth 
which shelter them ; their more or less plump appearance depends on 
hygrometric conditions, and they are not always of the same form. 
When first deposited, the yolk is much denser than the surrounding 
albumen, but it is not provided with any proper vitelline membrane. 

At first the changes occur very slowly, but soon they succeed 
one another more rapidly. First one and then the second polar 
globule appears, and, as a rule the latter is somewhat smaller. In 
dealing with the formation of the female pronucleus, the author 
points out that it constantly remains near the surface of the vitellus; 
its diameter may eventually attain one-fourth the diameter of the 
whole vitellus, or, in some cases, one-third. When treated with 
acetic acid, the female pronucleus is modified in shape by the forma- 
tion of a number of deep wrinkles and folds ; when with osmic acid 
(and subsequent staining in carmine), it has a delicate and even 
outline, and its form is spherical, pyriform, or oviform. Soon after 
extrusion, a number of small ovoid bodies of high refractive power 
are to be found near the vitellus, presenting a filamentous appearance 
in some cases; they are, doubtless, all spermatozoa; they may be 
present in great quantities, and even form “trains” through different 
parts of the albumen. In one case an undulating membrane was 
noted in a spermatozoon. 

After dealing with the characters of the male pronucleus and its 
history, the author passes to cleavage; here he finds that the first 
cleavage nucleus does not have a morphological existence; this is 
explained by assuming that the acceleration at this stage of the 
ontogeny is so great that the division of this future structure is begun 
before it has an actual independent existence, He is further of 
opinion that a differentiation commences in the superficial portion 
of the yolk, which is the first step toward the formation of a cell- 
membrane, and that this differentiation is proportional to the advance 
of cleavage. 

Jt is impossible to enter into the details of the elaborate account 
of previous naturalists’ observations which form the great bulk of 
this communication, which was apparently in the press before the 
publication of Mr. Balfour’s systematic treatise. 


Kidney of Chiton.*—Mr. A. Sedgwick gives an account of the 
structure of the kidney of Chiton, which is a paired gland constructed 
on the type always found in molluscan renal organs. It consists of— 

1. A duct opening to the exterior in the pallial groove behind 
the generative opening, and internally into the pericardium. 

2. Glandular ceca opening into this duct. 

The duct may be described as consisting of three parts :—(1) 
The part into which the glandular ceca of the kidney open. This 


* Proc. Roy. Soc., xxxiii. (1882) pp. 121-7 (2 figs.). 
N 2 


180 SUMMARY OF CURRENT RESEARCHES RELATING TO 


part is open to the exterior behind. In ‘front it bends round, and 
runs backwards to about the level of the 5th shell plate, where 
it changes its character, and is continuous with (2) a duct containing 
brown colouring matter in the columnar cells lining it, and receiving 
no glandular ceca. This part extends back to the level of the last 
gill, where it turns outwards, and becomes continuous with (8) a part 
running forward for a short distance close to the lateral nerve, and lined 
by large ciliated columnar cells. This opens in front at the level of 
the penultimate gill into the pericardium. The author expected to find 
the communication between the two parts of the renal duct behind, 
in the region of the bladder, and for some time was puzzled at not 
finding it. Mr, Balfour however suggested that the communication 
might possibly be found in front, reasoning from the analogy of the 
structure of the kidney in other Mollusca, and on examining the 
anterior part more carefully, the two parts of the gland were found 
to be communicating. 


Morphology of Neomenia.*—Messrs, A. Kowalevsky and A. F. 
Marion believe they have made the somewhat remarkable discovery 
that all naturalists who have examined this form have mistaken the 
_ posterior for the anterior end. They are enabled to show that the 
“Jateral glands” of Tullberg are salivary glands, and that the organ 
called the radula is really the penis. The description of the present 
writers is in accordance with that of Proneomenia as lately given by 
A, A. W. Hubrecht; ft but we reserve details tiil the publication of 
their fuller paper. 

In another paper { Hubrecht affirms his belief that it is the 
authors and not previous investigators who have misunderstood the 
matter. 

Molluscoida. 


Organization and Development of the Ascidians.s—A proper 
body-cavity in the Ascidians has been found by E. van Beneden to 
exist only in the larve. The species chiefly examined were Phallusia 
mentula, P. mamillata, Ciona intestinalis, Perophora listerit and Clavel- 
lina Rissoana. 

The larval mesoderm is found to consist of a right and a left 
lamina, derived from the primitive endoderm, and limited to the pos- 
terior part of the body. Each of these plates is divided into a posterior 
portion, formed of a single layer of cells, and giving rise to the 
muscle-cells of the tail, and an anterior one, which in Perophora 
and Olavellina is bilaminar and encloses a cleft opening into the 
alimentary canal and roofed in above by the chorda dorsalis, 

At a later period the anterior mesodermic cells lose their epithelial 
character, acquiring that of the adult blood-corpuscle, and becoming 
distributed to the epiblast, the central nervous system, and the hypoblast 
of the alimentary tract. A similar change comes over the endodermic 
cells of the floor of the neuro-intestinal canal, and the scattered cells 
give rise to the blood-corpuscles, the connective tissue, the body- 


* Zool. Anzeig., iv. (1882) pp. 61-4. + This Journal, ante, p. 31. 
} Ibid., pp. 84-6. § Comptes Rendus, xcii. (1881) pp. 1238-41. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 181 


muscles, the pericardium, and the sexual organs. In the bud of 
Perophora all these parts arise from the blood-corpuscles contained 
between the epi- and hypoblast. 

In the adult of Perophora the wall of the heart is unilaminar ; 
and the protoplasm of the deeper parts of its constituent cells takes 
on the structure of muscular fibrils. There is no cardiac endothelium. 
The wall of the heart is only a continuation of the visceral fold of 
the pericardium. This comes about from the fact that the mass of 
mesodermie cells from which the pericardium is developed is bilaminar, 
and a cavity appears between the lamin, forming the pericardiac 
cavity ; the inner lamina encloses a chamber which fills with cor- 
puscles, and it becomes the wall of the heart. 

In the primitive mass of mesodermic cells destined to form the 
sexual organs an excentric cavity appears, becoming the sexual vesicle ; 

this divides into an exterior, female, and an interior, male portion ; 
both are hollow and open into a long common tube formed of flat cells, 
which lies between the intestine and the gastro-cesophageal part 
of the alimentary canal, ending blindly at each extremity. This tube 
by growth becomes folded on itself, and its external section becomes 
the oviduct, its inner one the vas deferens; the posterior inflated end 
of the latter becomes the testis, which, single at first, becomes multi- 
lobate. The ovary arises by the conversion into germinal epithelium 
of the flattened epithelium of the posterior end of the oviduct; the 
primitive ova thus formed become imbedded in the investing con- 
nective tissue and form a follicular mass. The ovum falls into the 
oviduct when mature. At first the vas deferens opens into the oviduct, 
but when the cxcal anterior end of the latter opens into the cloaca, 
the opening of the former reaches the cloaca also and becomes inde- 
pendent. The strong analogies which exist between the development 
of the pericardium and the sexual vesicle show that if the pericardiac 
chamber is homologous with that of Vertebrata, that of the sexual 
organs corresponds with the abdominal cavity. 

The body-cavity (“ enterocele”) of the larva completely disappears, 
for the epithelial cells which line it expand into a ‘“ blastocele,” and 
then form a continuous mass, or mesenchyme. There is thus no 
radical distinction between the mesoderm and mesenchyme as held by 
the brothers Hertwig to be the case. In their structural characters 
and in the mode in which the nerves terminate in them, the muscles 
of the adult approach the smooth muscular tissue of Vertebrata, but 
those of the heart are peculiar in consisting of parallel fibrils placed 
in the deeper parts of epithelial cells. 

It follows from the above facts that the mesenchyme has not 
always the same origin or the same anatomical importance in the 
animal kingdom. In the Ceelenterata and Vertebrata it is a primitive 
mesenchyme, as being produced by contact with an epithelium ; in the 
Ascidians it is secondary, for it results from the dissociation of the 
cellular elements of an epithelium (the original mesoderm). The 
muscular fibres which originate from cells of the mesenchyme 
appear to be always fibre-cells, whether the mesenchyme is primitive 
or secondary. 


182 SUMMARY OF CURRENT RESEARCHES RELATING TO 


“Challenger”? Ascidians (Culeolus).*—Dr. W. A. Herdmann 
forms the genus Culeolus for a series of six new species of pedunculated 
simple Ascidians, belonging to the family Cynthiidw, and having 
several anatomical peculiarities distinguishing them from all hitherto 
described genera. The nearest ally of Culeolus is Boltenia, and these 
two genera have been placed together as a sub-family, the Boltenina, 
characterized as Cynthiide which have the body pedunculated, the 
tentacles compound, and the branchial sac with more than four folds 
on each side. 

Culeolus is distinguished from Boltenia by its remarkable branchial 
sac, and by the external character that its branchial aperture is tri- 
angular, and its atrial aperture bilabiate, while in Boltenia both apertures 
are four-lobed. The branchial sacis in all respects, except the possession 
of a certain number of longitudinal folds on each side, the simplest 
form known among simple Ascidians. It may be described as a simple 
network, formed by two series of vessels crossing at right angles and 
communicating at the points of intersection. In its vessels is found 
an extensively developed system of calcareous spicules of considerabie 
but varying size, often much ramified, and having a very characteristic 
appearance from their gentle curves and blunt ends. 

One of the species, C. murrayi, is described in detail, anatomical 
and histological, while the other five are not so fully treated, but the 
different systems in each are compared with those of the type, and 
the modifications are pointed out. 

All the species are from upwards of 600 fathoms ; five are from 
over 1000 fathoms, four from over 1500, and two from upwards of 
2000 fathoms. They all belong to the abyssal fauna. It is note- 
worthy that these six species, the only deep water Boltenine, all 
belong to one genus, notwithstanding their wide distribution in space, 
one species being from the North Atlantic, two from the Southern 
Ocean, one from the South Pacific, one from the North Pacific, and 
one from the centre of the Pacific Ocean on the equator. 


Embryonic Membranes of the Salpide.j—Dr. J. Barrois finds 
that some of the discrepancies between the accounts of Salensky and 
Todaro, which appeared almost simultaneously, are to be ascribed to 
the extreme diversity in the developmental history of the members of 
this group of the Tunicata; and he is able to speak to the correctness 
of their accounts of the different forms examined by them. 

The first species now described is Salpa maxima, and we see that 
much that is true of it is true of other forms also, The appendages 
are either extra-foetal or embryonic. When the ovum has reached its 
definite position its follicle has the form of a rounded vesicle, with 
three thick walls, and is attached to the base of a shallow depression 
in the wall of the branchial sac; segmentation is now somewhat 
advanced. The follicle becomes oval, and the depression becomes 
converted into a cul-de-sac, which projects considerably into the 
interior of the respiratory cavity ; in this cul-de-sac the follicle is 


* Proc. Roy. Soc. xxxiii. (1882) pp. 104-6 (1 fig.) (Abstract only). 
t Journ. Anat. et Phys. (Robin) xvii. (1881) pp. 455-98 (2 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 183 


completely lodged. This process becomes more and more marked, 
and the egg begins to exhibit a segmentation cavity. Two grooves 
appear, and divide the cul-de-sac into three portions; as they deepen, 
the sac gets the form of an irregular mass, and the median portion 
gives rise to the peripheral layer (placental membrane, Todaro) of the 
placenta ; in the next stage the lower wall of the follicle increases in 
size and gives rise to a mass of several rows of cells, which will go to 
form part of the placenta. The fold formed from the inferior 
divisions of the sac forms two layers of the circular fold, which is 
destined to cover the whole of the embryo (caduca externa, Todaro). 
During this process the superior division of the cul-de-sac has become 
much more completely attached to the upper portion of the follicle. 
The circular fold grows more and more over the embryo. 

' The embryonic appendages are thus developed: the outer layer 
‘of the embryo becomes applied to the inner face of the follicle, its 
lower portion, with which there is connected the mass formed by the 
internal layer, separates from this follicle, and so gives rise to the 
placental cavity; that portion of the outer layer which invests it is 
the fetal placenta, the rest of the embryo forms the endoderm and 
apparently the rudimentary ectoderm. A little later the young Salpa 
becomes invested in a single layer which forms its skin, the endo- 
dermic mass becomes completely detached from the fcetal placenta, 
and forms a nucleus around which the principal organs are developed. 
The foetal placenta unites with the placental membrane to form the 
complete placenta, a third layer in which is formed from the mass 
of several rows of cells, already mentioned. The foetal placenta 
increases in size and then undergoes a retrograde development; thus 
the structure of this part is simplified. The remaining stages are 
simpler. 

There are, then, three parts concerned in the formation of the 
embryo and its appendages ; two, the follicle and an expansion of the 
wall of the branchial sac, are developed from the mother ; the third is 
formed from the egg. The upper portion of the primitive cul-de-sac 
forms the outer wall of the primitive incubation-cavity, the fold at 
the base bounds the definite uterine cavity, while the median portion 
gives rise to the placental membrane. From the ovum the embryo 
proper and the foetal membrane are developed. The author thinks that 
the so-called placental membrane has really no placental function, but 
rather serves to-keep the incubation-sac in its place in the middle of 
the great uterine cavity. Reduced to its simplest terms, we may say 
that the mother furnishes two incubatory pouches, connected by a 
membrane which maintains the first within the second pouch, and the 
maternal placenta; while to the embryo there is to be ascribed a 
simple expansion, which, like the allantois of the Mammalia, is destined 
to form the central portion of the placenta. 


Modifications of the Avicularia in Bryozoa.*—Mr. T. Hincks 
considers that there can be no reasonable doubt that the vibraculum 
is a derivative from the avicularium and not an independent modifica- 


* Ann. and Mag, Nat. Hist., ix. (1882) pp. 20-5 (4 figs.). 


184 SUMMARY OF CURRENT RESEARCHES RELATING TO 


tion of the oral valve of the zocecium, and he shows that the leading 
stages exist in Schizoporella ciliata. Sometimes a moderately short 
avicularium of the ordinary type occurs ; in other cases the mandible 
is more or less prolonged into a straight and slender spine. In speci- 
mens from the Queen Charlotte Islands the mandible has altogether 
lost its lid-like character and is now a very tall membrano-chitinous 
appendage, commonly exceeding in length the entire cell ; from Ceylon 
or Bass’s Straits still another form is known, in which the spinous 
process of the avicularium is furnished on each side with a delicate 
membranous expansion. 

It is suggested that in the avicularian appendages is to be found 
a ready adaptability to change of circumstances, and Mr. Hincks 
considers that these observations bring out very forcibly the insta- 
bility of the avicularian structure, so that he cannot agree with those 
who assign a high value to the appendicular organs for the purposes 
of classification. 


Arthropoda. 


a. Insecta. 


Flight of Insects.*—R. von Lendenfeld, after some general con- 
siderations on locomotor organs, points out that insects with one pair 
of wings appear to be the most highly organized and possess the 
largest brain. Before the Jurassic period no two-winged insects seem 
to have existed; these later ones would appear to have been derived 
from the four-winged forms. The “dipterous” type seems to have 
been developed along two different lines; while in the Lepidoptera 
Rhopalocera the anterior wings are the larger, in the Orthoptera 
genuina the hinder are the larger; allied to the former are the 
Sphingide and the Hymenoptera with the anterior wings much 
the larger, and they culminate in the true Diptera in which the 
anterior wings are alone developed. On the other hand, the Ortho- 
pterous form leads through the Coleoptera, where the anterior wings 
form elytra, to the Strepsiptera, in which the anterior wings are 
aborted; lower than all these are the Neuroptera planipennia and 
the Libellulide in which both pairs of wings are equal in size. 
In discussing the question of the homology of the wings, the author 
states that his own observations incline him to the view of Fritz 
Miiller that they are derived from lateral processes of the dorsal 
plates of the wings on which they are found, and that they are not 
modified tracheal gills. 

The rest of the paper deals in detail with the characters presented 
by the Libellulide. A diaphragm of chitin separates the muscles 
for the wings from those for the legs; the exoskeleton is made up of 
a number of thin chitinous plates; there are various methods of 
articulation, some of which are exactly comparable to those that are 
found in the Vertebrata. Sixty-two separate skeletal parts are named 
and described. The wings are not only similar in structure but in 
action and function ; the quantity of blood which makes its way into 


* SB, Akad. Wiss. Wien, lxxxiii. (1881) pp. 289-376 (7 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 185 


them is very much less than it is, for example, in the Lepidoptera, and 
their wings are therefore exceedingly light. 

The sixteen muscles and two ligaments are named and described, 
and an account is given of the method adopted for securing instan- 
taneous photographs of the insects’ wings. T'wo phases are to be 
distinguished in the movement of the wing, the movement from behind 
forwards, and from in front backwards; in both, however, there is 
an upwardly acting force; with this, there are associated other 
movements, resulting in the course of the wing being a more or less 
complicated curve, the directions of which depend of course on the 
extent to which these other forces act. 


Nucleus of the Salivary Cells of the Larve of Chironomus.*— 
E. G. Balbiani reminds his readers that in 1876 he noted how the 
epithelial cells of the ovary of the Orthopterous insect, Stenobothrus 
pratorum, contained in their nuclei not ordinary nucleoli, but a large 
number of small subequal granulations, which he compared to a mass 
of bacteria. He showed that these united to form the filaments of 
the nuclear figures which characterize the different stages of the 
division of the nucleus (Karyokinesis), and that it followed that the 
nuclear filaments were not, at first at any rate, homogeneous, but 
formed of granules set along a single line. Confirmatory observations 
have lately (1881) been made by W. Pfitzner on the Salamander ; but 
instead of using his complicated method of demonstration, the author 
has found that it is sufficient to treat fresh cells with acetic or chromic 
acid: when the action is prolonged the globules may be seen to fuse 
more or less completely with one another, and to give rise to filaments 
which are sometimes varicose, and sometimes completely homogeneous ; 
it is under this condition that the nuclear filaments have generally 
been described and figured. 

The salivary glands of Chironomus are two flattened organs, formed 
of a small number of large clear cells, with large nuclei, trausparent, 
like the cells themselves ; in the nuclei there are two large nucleoli 
formed by a granular refractive substance, and containing a more or 
less large number of vacuoles. In addition to these, there is a pale 
body of the form of a cylindrical cord, which is coiled upon itself in 
an intestiniform fashion. In larve of some age it is often broken up 
into filaments of varying length which may either remain free, or 
become attached to the envelope of the nucleus. Some little way 
from each extremity the cord is suddenly swollen out, and this may 
be described as a ring; when the cells are allowed to die in the 
blood of the animal, the ring, which was previously difficult to detect 
on account of its paleness, becomes finely granular, and so more 
evident. In living cells it is perfectly homogeneous, being neither 
granulated nor vacuolated. Entering into a detailed account of the 
cord, the author describes its transverse strie and the disks of which 
it seems to be composed. 

The influence of reagents reveals a difference in chemical com- 
position; distilled water causes the cord to swell, till it becomes 


* Zool. Anzeig., iv. (1881) pp. 637-41; 662-66, 


186 SUMMARY OF CURRENT RESEARCHES RELATING TO 


almost invisible; the nucleoli resist the action for a longer time. 
Acetic or chromic acids (1 per cent.) or concentrated picric acid bring 
out the details of the nucleus, the disks of the cord, the rings at the 
extremities, and the nucleoli. After giving an account of the action 
of various colouring matters, the author says that he thinks no one 
will doubt that the cord is homologous with the intranuclear network 
of other nuclei; and that it is not, as most have supposed, really 
formed of homogeneous filaments, continuous with the nuclear mem- 
brane, and largely ramifying and anastomosing. The network has 
nearly always been described after the action of reagents on it; it is 
now seen how much these affect its original characters. 

The nuclei of the cells of the larvee of Chironomus may be looked 
upon as very complex elements, offering a true organization, if by that 
term we understand an assemblage of parts having fixed and constant 
relations to one another, and fulfilling special functions. As to the 
functions of this apparatus and its mode of activity, hypotheses are at 
present useless; not only animal, but also vegetable cells must be 
more closely studied, and the two carefully compared. In conclusion, 
notice is taken of the observations of Baranetzky ou the pollen-cells 
of Tradescantia, where obscure transverse striz were seen in the 
nuclear filaments, and a clear intranuclear substance, comparable to 
that found in Chironomus, was detected. 


y- Arachnida. 


Structure of the Dermaleichide.*—After describing in detail 
the mouth-parts of these Arachnida, Dr. G. Haller directs attention 
to certain characters in the digestive tract which point to their close 
affinity with the Tyroglyphida and Dermacara; the tract being 
simple, and the saccular stomach divided into two parts, lying one 
behind the other, and not differing in function. 

So again, in the structure of the male organs we find a not incon- 
siderable resemblance to the Tyroglyphida ; the testes and their ducts 
are paired, the seminal vesicle and reproductive organ are unpaired, 
while the male is provided with organs of attachment, and with 
accessory organs developed on the extremities. Further investigation 
into details proves, however, that we have here to do with forms of a 
more lowly organization. Two, and in some cases three, different 
forms of females were observed. The first of them was impregnated 
by the male, but had no indications of any generative organs; the 
next had a matured ovum in its oviduct. The former of these is really 
an eight-legged larval form, and it is only in the next stage that the 
matured female is really present. The author justly directs attention 
to this remarkable peculiarity. 


5. Crustacea. 


New and rare French Crustacea.;j—M. Hesse here describes 
Bimonaste bicolor and Scotophilus tricolor, two parasitic Copepods 


* Zeitschr. f. wiss. Zool., xxxvi. (1881) pp. 367-88 (2 pls.). 
+ Ann. Sci. Nat. (Zool.) xi, (1881) art. No. 8, 19 pp. (2 pls.), 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 187 


which he found living in Ascidians. He also gives a further account 
of Notopterophorus papilio and N. bombyx (see Fig. 28), remarkable 
forms in which the body is provided with 
large delicate membraneous lamelle, not 
unlike wings of Lepidoptera. The head 
has a kind of covering which is sur- 
mounted by two narrow expansions, longer 
in the female than in the male, and not 
found in the young. The wing-like expan- 
sions are attached to the dorsal portion of 
the thorax; they are evidently too delicate 
for any marked action, and it is probable 
that they are able to insinuate themselves 
between the tisues of their host; they can 
move with some rapidity, after the fashion 
of a butterfly’s wings. When young, these 
curious creatures resemble a Monoculus in 
form. A systematic definition of the two 
species is appended, and reference for 
further details is made to the author’s 
earlier papers (1864 and 1865.) 


New British Cladocera from Grasmere f 
Lake.*—Professor Ray Lankester points 
out that previous to his identification of VA f 
Leptodora hyalina Lillj., and Hyalodaphnia ) 
Kahlbergensis Schodl, as British Cladocera 
in specimens from the Olton reservoir, few of the remarkable 
forms of Cladocera which occur in the larger lakes of the Continent, 
had been recognized as occurring in this country; but the list has 
now been extended by the observations of Mr. C. Beck, who, last 
summer, examined the Entomostracous fauna of Grasmere Lake, 
Westmoreland, and found the following species, three of which are 
new to British waters. 

1. Leptodora hyalina Lilljeb. ¢. Taken Sept. 16th. 

2. Hyalodaphnia Kahlbergensis Schédl. Abundant Sept. 9th to 

16th. 

3. Holopedium gibberum Zaddach. ‘Thirty specimens, each en- 

cased in a gelatinous globe, Sept. 7th to 16th. 

4, Latona setifera 6 and 2 Straus(Weissman). Sept. 3rd to 14th. 

5. Bythotrephessp. Sept. 14th. This appears to be a new species, 
distinct from the Bythotrephes longimanus of Leydig. 

At the same time, Mr. Beck observed the following, already 
known to Baird as British species, but some being of rare occurrence : 
Sida crystallina O. F. Miller (Straus genus) ; Daphnia vetula Miiller, 
D. reticulata Jurine; Eurycercus lamellatus O. F. Miller (Baird 
genus); Alona quadrangularis Miller (Baird genus); and Peracantha 
truncata Miller (Baird genus). 

It appears probable that in lakes where species of the Salmonid 


* Ann. and Mag. Nat. Hist., ix. (1882) p. 53, 


Fic. 28. 


se 
te ates sel WES cae 
VE ama AU 
= HS R® & . us . 
(GaSe SS 
Cy JN \ “A 


7. 


188 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Ceregonus are found, there also will be found the large deep-water 
Cladocera, such as Holopedium and Bythotrephes, which serve these 
fish as food. 


The Entoniscida.*—Prof. R. Kossmann finds that only five previous 
papers by three investigators (I, Miller, Fraisse, and Giard) form 
the bibliography of this group. European forms are said to be 
hermaphrodite, while the Brazilian appear to be dicecious, but the 
author has found the males of the former, though their relatively 
smaller size is obviously a difficulty which may have caused the 
earlier incorrect statement. Two genera—Hntoniscus and Entione— 
are recognized, and the differences between their males pointed out. 
In their case, as in that of the females, the peculiarities of the group, 
and their common characters with the Bopyride are insisted on; the 
differences between the females of the two genera of Entoniscida are 
duly noted, and the views of earlier naturalists critically examined. 
The author does not think it probable that there is any change of 
host, as Fraisse has supposed. 

It is pointed out that two larval forms obtain with E. cavolinii ; 
some of the differences which previous investigators have detected 
and looked upon as specific, he believes to be due to differences in 
age, and the tegumentary glands discovered by Fraisse have not been 
made out by Kossmann. : 


The Bopyride.t—In this third contribution to a knowledge of 
these forms, Prof. R. Kossmann deals with Jone thoracica and Cepon 
portuni un. sp. (found in Portunus arcuatus), of which he gives a careful 
account, with especial reference to the gills, and the differences 
between the male and female. So rare are these forms, that 10,000 
Brachyura were in vain opened by Salvatore Lo Bianco, of the Naples 
Zoological Station, before it could be said that a Bopyrid was to be 
found in any European Crustacean. The parasitism of this creature 
is neither common nor rare, but only gives rise to local epidemics. 


Vermes. 


Anatomy and Histology of Scoloplos armiger.t—W. Mau has 
selected this common form for a study of the Polychxtous Annelids. 
The methods of examination have comprised the investigation of 
living forms, and of specimens hardened by being killed in picric or 
chromic acids, in which they were left for a fortnight; after washing, 
they were placed first in dilute and then in absolute alcohol; other 
specimens were killed in dilute, then placed for some time in stronger, 
and, finally, in absolute alcohol. The examples best adapted for 
sections were found to be those that had been treated with chromic 
acid. The most suitable colouring matters were saffranin, alum- 
cochineal, and picro-carmine. Sections were cut by the microtome 
or the razor after imbedding in paraffin. 


* MT. Zool. Stat. Neapel, iii. (1881) pp. 149-69 (2 pls.). 
| t Ibid., pp. 170-83 (2 pls.). 
{ Zeitschr. f. wiss. Zool., xxxvi. (1881) pp. 389-432 (2 pls.).’ 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 189 


After describing their habits and general form, the author gives 
a detailed account of their various organs. The cuticle is, as com- 
pared with that of the Oligocheta, excessively delicate (not more than 
0-002 mm. thick); it is not provided with any tactile sete or other 
processes, and when fresh, is with difficulty separated from the 
hypodermis ; it is traversed by pore-canals, and there are, in addition 
to these, rounded lacunz which are arranged in parallel rows. The 
hypodermis is best examined after treatment with chromic acid and 
alum-cochineal or saffranin; the latter colouring agent brings out 
the nuclei and the rod-shaped or spindle-shaped bodies; these 
are found in the intercellular substance, and there are in addition 
a number of pigment-granules. The muscular system is extra- 
ordinarily well developed, and consists of circular, longitudinal, and 
dorso-ventral muscles, as well as of obliquely-set muscles in the 
anterior region. As was to be expected, the ccelom or body-cavity is 
broken up by dissepiments into a number of chambers, which are most 
distinct in the posterior portion of the body. Into the formation of 
these dissepiments the dorso-ventral muscles enter; and the cavity 
only communicates with the outer world by means of the orifices of 
the segmental organs, the large pores which are found in the terri- 
colous Oligocheta being here completely absent. 

The most important point noticed in the enteric tract would 
appear to be the ceca, which are developed in its more posterior 
portion, and which have their walls specially modified; no definite 
opinion can be given as to their function, but they would appear to be 
secreting organs; they have some resemblance to the swim-bladder- 
like organs lately described by Hisig in the Syllidea,* but in this form 
they never contain gas, and their walls are not contractile. Passing 
to the nervous system, we find the author including the sub-cesophageal 
ganglia in the brain; the ventral cord is surrounded by muscles, and 
is not, as in most Ariciide (McIntosh), outside them. Transverse 
sections show the existence of a more or less rounded space, which 
leads to a belief in the presence of a canal extending through the 
ventral medulla. 

The circulatory system has closed vessels with proper walls, and 
there would seem to be no lacune; the stomach is richly provided 
with blood-vessels, and there is a pair of transverse vessels in each 
segment, which are, for the greater part of the body, eminently con- 
tractile. The blood is more or less red. 

At the time of sexual maturity, the hinder part of the body of the 
male is whitish, and that of the female brownish-yellow in colour; 
the ova or sperm fill up the space between the intestine and the sides 
of the segments, but the generative products of one segment are pre- 
vented by the completely developed septa from making their way into 
another segment. The ova arise in a cellular tissue which lies near 
those vessels which intervene between the walls of the intestine and 
those of the body; the ova do not break away till they are completely 
matured, and they then do not, as in some other Annelids, float freely 


* See this Journal, ante, p, 44. 


190 SUMMARY OF CURRENT RESEARCHES RELATING TO 


in the ecelom, but are confined to the segments in which they are 
developed. The spermatozoa are developed in great quantities, and 
are, when ripe, excessively active; they resemble in form those of 
Magelona. 

As efferent ducts for the products, we have the so-called segmental 
organs; they differ somewhat from those of other Chetopods, being 
tubular structures, in which it is not possible to distinguish different 
regions; the whole is very short, and only just extends into the 
ccelom; the external and internal orifices are somewhat widened out, 
but are not specially differentiated. They are not developed in the 
anterior portion of the body, where their place appears to be taken 
by a coil of cells with distinct nuclei; these are regarded as glandular 
organs, but no efferent ducts can be detected, and their development 
must be studied before their homologies can be exactly defined. The 
body easily breaks, and regeneration was found by experiment to be 
somewhat complete, 22 segments appearing where 42 had been before, 
20 where there had been 33, 26 for 40, 27 for 63, and 24 for 68. 


Parasitic Eunicid.*—-Dr. J. W. Spengel, in describing Oligo- 
gnathus Bonellie, remarks that parasitic Polycheta would seem to 
be very rare, the young Alciopids which are parasitic in Ctenophora 
affording the only other real exception to the rule that the Polycheta 
lead a free life. On examining some Bonellie at Naples, the author 
found in their coelom an orange-coloured cord which attracted his 
attention by its lively movements. Not more than 10 cm. long, 
with a thickness of 1 mm. in its middle, it had more than 200 
segments, together with a region of incomplete segmentation. The 
maxillary apparatus was rudimentary, and there were only three small 
teeth on the upper jaw. In the observations which follow his 
systematic account, the author enters into some comparison of the 
characters presented by this new form with those which are to be 
seen in some of its allies. 

In dealing with its nervous system, the author points out that, 
while the cesophageal commissure contains but few ganglion-cells, 
there is a well-marked sub-cesophageal ganglion in the second 
segment; in the next six or seven, there are, as in it, two ganglia; 
further back, the swellings are inconsiderable ; the elements of the 
ventral cord are arranged in typical fashion, save that the fibres form 
not two but three connecting cords. When compared with its allies, 
it is shown to be remarkable by the possession of a secondary ganglion 
in each segment, by the great breadth of its anterior ganglia, and 
by the close connection between the ganglia and the epidermis. In 
it the ganglia are all subequal, but in Halla the anterior ganglia 
contain a few giant-cells, each of which is provided with a special 
thick investment, formed of concentric fibrous layers with numerous 
spindle-shaped nuclei. The tubular sheaths thus formed are com- 
parable to the “ fibres tubulaires gigantesques” long since described 
by Claparéede. After discussing the arrangements found in other 
forms, the author concludes that it must still remain uncertain 


* MT. Zool. Stat. Neapel, iii. (1881) pp. 15-52 (3 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 191 


whether the tubes filled with pale soft contents which traverse the 
central medulla of so many Annelids, are, or are not, all homologous 
structures; there can be no doubt that the tubular fibres of Halla 
and Arabella are the sameas the neural canals or giant fibres of the 
Oligocheta ; but much still remains to be made out as to their connec- 
tions with the cells and their function. ‘This, however, is certain 
that the Annelida, no less than the Arthropoda and the Vertebrata, 
present marked variations in the size of their ganglion cells. Passing 
to the peripheral nerves, the author demonstrates the circular 
character of this system, which has already been detected in Sipun- 
culus and Hchiurus. A sympathetic system was found in longi- 
tudinal sections of the body, when pale fibres were seen to be running 
parallel to the ventral medulla, and apparently connected with it by 
secondary ganglia. 

The greater part of the enteric canal is very simple, the only 
- complications being in the anterior region. A series of regular folds 
are found behind the mouth, and project considerably into the lumen 
of the tube; their substance is mainly composed of muscle, and, as 
compared with other Lumbriconereids, they are rudimentarily de- 
veloped in Oligognathus. After describing in detail the structure of 
the jaws, the author refers to a canal which opens on the ventral 
surface of the anterior portion of the enteron, and which he thinks, 
though material has prevented from coming to a definite conclusion, 
may be homologous with the secondary gut of the Capitellide. 

The segmental organs present nothing specially worthy of note 
here, and the reproductive organs were not matured in any specimen 
examined. 


Development of Anguillula stercoralis.*—Professor E. Perroncito 
gives an account of his observations on the development of this 
endoparasitic Nematode outside the human body. After a medical 
history of a patient afflicted with this worm, and who, till he 
went to work in the St. Gothard Tunnel, was remarkably healthy, 
he states that he was able to convince himself that A. stercoralis may 
be developed in the intestine of man, without the necessity of any 
free-living larval stage. When the embryo leaves the egg it is 
0:2 mm. long, and 0-01 mm. broad. The larve leave the body at 
different stages of development ; and when cultivated at a tempera- 
ture of from 22-25° C., do not all complete their development, or 
become sexually mature. In what may be known as the second stage, 
or that which is reached after sixteen or seventeen hours, they are 
longer and more delicate, are enclosed in a delicate capsule, and the 
stomach has lost its chitinous armature; they now have on the whole 
a very close resemblance to the larve of A. intestinalis. Those larvae 
which attain the adult condition, retain the capsule till they attain 
maturity ; they may become as much as 4 a mm. long. The sexes 
are separate, and the female is about a third longer and broader than 
the male, and contains about thirty eggs. 

After discussing the zoological relations of this helminth, 


* Journ. Anat. et Physiol. (Robin) xvii. (1881) pp. 499-519 (1 pl.). 


192 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Professor Perroncito elevates it into a new genus, to be called 
Pseudo-rhabditis, and he gives a technical definition. The larvae 
are always killed at 48°5° C.; doliarine treated with hydrochloric 
acid occasionally, but not always, was a fatal poison, 1 per cent. 
solution of phenic acid was found to be constantly poisonous, as were 
other drugs, including an ethereal extract. of male fern, especially 
when an alcoholic tincture of the same was added. The patient 
already mentioned was supplied by the author with an alcoholic 
liquor called fermet, and this was found to be mortal to the 
parasite. 


Cercaria with Caudal Sete.*—Mr. J. W. Fewkes describes a 
Cercaria, or larval Trematode, which differs considerably from any- 
thing he has been able to find in any published figures. The 
interesting feature is the Annelid character of the tail, a charac- 
teristic which he considers may indicate some new relationship 
between the Trematoda and the Annelida. 

The Cercaria is marine, and always found at or near the surface 
of the water. Its length, when body and tail are extended, is about 
zz inch. The body walls are very transparent. Its motion through 
the water, as far as was observed, consists entirely of a “jerky” 
motion, brought about by the powerful strokes of its very muscular 
tail, a motion resembling very closely that of the nauplius of Balanus. 
With moderate magnifying powers, the motions of the tail are so 
rapid that they cannot be followed by the eye. 

The head is very variable, its shape being sometimes contracted 
into a spherical ball, and at other times extended into an oval. At 
the extremity is the mouth. The stomach occupies a large part of 
the anterior central. part of the body, and from it there is continued 
backward, a pair of blindly-ending vessels as in other Cercaria. The 
most prominent structure of the body is a large medially placed 
sucker. 

The tail is the most peculiar feature. Its general shape is hardly 
characteristic, and it owes its interest to the bundles of setz arranged 
on opposite sides at intervals along the whole length. These sete, 
of which there are many in each bundle, are straight, inflexible, 
and moved by muscles in the walls of the tail. Their resemblance 
to the sete found in the segments of Annelids is very great. 


New Type of Turbellaria.t—W. A. Silliman describes a singular 
worm which he found parasitic on a large green Nematoid, which was 
apparently parasitic on Hchinus sphera. 

The body of the animal is sublanceolate, 2-25 mm. long, with an 
average breadth of 1:5 mm., and of a light brown colour. The 
suckers and hooks so characteristic of ectoparasitic Trematoda are 
wanting. 

The epiderm is formed of tolerably regular hexagonal ciliated 


* Amer. Journ. Sci., xxiii. (1882) pp. 134-5 (1 fig.). 
+ Comptes Rendus, xciii. (1881) pp. 1807-9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 193 


cells, whose nuclei are very plainly visible. These cells are covered 
with a thin chitinous cuticle, perforated for the passage of vibratile 
cilia, by which the animal can move over the body of its host. The 
cilia of the ventral face are much longer and stronger than those of 
the dorsal. Beneath the epidermis is a basal membrane containing 
the brown pigment to which the colour of the animal is due. 

No water-vascular system was observed, but its non-existence 
cannot be positively asserted. 

The genital organs are the most remarkable characteristics of the 
animal. The male organs include numerous testicles and a penis 
enclosed in a sheath ; the female organs a double ovary and pseudo- 
vitellogen, a uterus, and vagina. ‘The testicles are placed in the 
anterior third of the body, and are in the form of small sacs, each with 
a very fine duct, which unite behind the intestine and debouch in the 
_ penis. The latter is a long canal of uniform diameter, which in a 
state of repose has numerous flexions. Its walls are muscular, and 
covered with a thin chitinous layer. It terminates in a sort of cirrus, 
-018 mm. in diameter. 

The uterus, like the sheath of the penis, is median, and situated 
below the latter ; it terminates towards the middle of the body in a 
cul-de-sac, and more often than not contains an egg enclosed in an 
ovoid shell, which has an extremely long and fine peduncle. The 
shell and its peduncle would be secreted by the cells which line the 
wall of the uterus. 

The pseudo-vitellogen occupies the second third of the body, and 
has the form of numerous ramified tubes, those on each side uniting 
towards the median line and debouching in the uterus. Immediately 
behind these openings are the ovarian cells; these are more or less in 
the form of a hand, of which the wrist communicates with the uterus, 
whilst the fingers are directed backwards and spread out. The eggs 
develope in the extremities of these fingers, and become larger in pro- 
portion as they advance towards the uterus. Their nucleiand nucleoli 
are very visible. 

The vagina, which is never found in the Turbellaria, but is well 
marked in the Trematoda, opens on the dorsal surface in the pos- 
terior quarter of the body, and thence runs forwards towards the 
uterus. At the plane of the opening of the ovaries it dilates into a 
receptaculum seminis with muscular walls, which communicates with 
the uterus by a narrow and short canal. 

This aberrant creature thus presents affinities (by the ciliated 
epiderm, digestive apparatus, male organs, and two ovaries) with the 
Turbellaria on the one hand, and (by the vagina and disposition of 
the pseudo-vitellogen) with the T'rematoda on the other. Seeing that 
the young Trematoda are ciliated, but later on lose their cilia, the 
Trematoda may be considered as modified if not degraded Turbel- 
larians. The animal in question being, therefore, a transition form, 
should represent a new suborder of Turbellaria. 

The author proposes to designate it Syndesmis, in order to 
express its morphological réle, and promises further details on the 
subject. 

Ser. 2.—Vok. II. ce) 


194 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Systematic Position of Balanoglossus.*—Professor A. Giard 
has some observations on the paper of Metschnikoff t on this form, in 
which he points out that the presence in its larva, Tornaria, of a 
very special heart (which he has never observed in the larve of any 
Echinoderm), the relatively late appearance of the ciliated circlets, 
and the existence of a muscular band uniting the aquiferous system to 
the median point of the eye-spots, all present difficulties which 
prevent us from at once accepting the view of the close relationship 
of the Enteropneusti and the Echinodermata. 

Attention is directed to one point of similarity; four years ago 
the author showed that, in the Hchinoidea, after the reproductive period 
has passed, the genital glands form culs-de-sac filled with very large 
elements which have no resemblance to generative cells, and have 
within them a large vacuole, which owes its appearance to the 
atrophy of the nucleus; in addition, there are in the cell small 
brownish concretions, similar to those found in the renal organs of 
numerous Invertebrates ; deutoplasmic elements which are, later on, 
absorbed by the developing genital cells, and a large number of 
crystals of phosphate of calcium are also present. From these 
observations the author concluded that, for a certain part of the year, 
the genital glands of Echinoids took on an excretory and a deuto- 
plasmigenous function. A renewed study of Kowalevsky’s memoir 
on Balanoglossus, showed the author that a very similar state of 
things was to be observed in that animal, but he here insists that it 
would be rash to give too much value to a morphological similarity 
which may be simply due to a similarity of function. A fair objec- 
tion would be raised by any one who should point out that nothing 
of the kind is to be observed in the Starfishes. At the same time, 
the absence of segmental organs in Balanoglossus would seem to be 
very significant. If we distinguish the excretory apparatus of the 
Invertebrata as (a) protonephridia, e. g. the organs of Turbellaria, 
Cestodes, Trematodes, Rotifers, &c., and (8) the deutonephridia, or 
segmental organs properly so called, we find that we cannot place 
with the former either the water system of Echinoderms, or that of 
Balanoglossus ; nor are they homologous with the modified deuto- 
nephridia. 

The relationship of Balanoglossus to the Tunicata is absolutely 
denied, the resemblances between them being regarded as purely 
analogous; provisionally, therefore, Giard accepts the general doctrine 
of Metschnikoff, without pretending to exactly define the genealogical 
position of this curious and interesting form. 


Nervous System of Platyhelminthes.t—Of the fourth and fifth 
parts of Dr. A. Lang’s contributions, the most important point is the 
discussion of the character of the nervous system as treated compara- 
tively. Comparing them with the Ctenophora, the only group of the 
Coelenterata which have a corresponding histological and anatomical 
differentiation of the germinal layers, the author points out that in 

* Bull. Sci. Dép. Nord, iv. (1881) pp. 372-8. 
+ See this Journal, i. (1881) p. 462. 
t MT. Zool. Stat. Neapel, iii. (1881) pp. 53-96 (2 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 195 


both the mesenchyma gives rise to muscular, nervous, and connective 
tissue. The nervous system of the Ctenophora consists of a nervous 
plexus scattered through the mesenchyma, of an ectodermal plexus 
with eight fibrous tracts, and of an ectodermal sensory body. In that 
of the Polyclades we distinguish a nervous plexus closely connected 
with the mesenchymatous musculature, which in all probability arose 
in connection with the musculature from the cells of that layer; a 
system of nerve-trunks, placed in the mesenchyma, connected by com- 
missures and anastomoses, and radiating from a single point; of these 
eight are specially noticeable. The third portion consists of sensory 
organs (eyes), with sensory nerves, the prime origin of which appears 
to have been from the ectoderm. The three parts are here in connec- 
tion with one another, and this, in addition to such differences as are 
due to adaptation, appear to be the only important points of distinc- 
tion between the two groups. 

. Starting from the Polyclades, we may note that differentiation has 
proceeded in two directions—the one associated with the degeneration 
of the parasitic, the other with the elevation of the free-living forms. 
The brain is the point at which all the nerve-trunks meet ; it is, there- © 
fore, largest in those forms in which the nerve-trunks are the best 
developed ; and its size, in the Polyclades, though they are the 
most primitive of the Platyhelminthes, should not be any cause for 
astonishment. Among the Trematoda, Tristomum. most nearly 
approaches them in habit and organization; the brain, however, is 
more simple. This simplicity is still more marked in Pleurocotyle and 
Distomum nigroflavum, where the brain is merely a transverse com- 
missure. In Amphilina and those Cestoda in which the scolex is but 
feebly provided with muscles, the brain is so feebly developed as to be 
barely distinguishable; where, however, as in the Tetrarhynchi, the 
musculature is more abundant, the transverse commissures are corre- 
spondingly better developed. 

In the Triclades the brain is feeble in the fresh-water forms; in 
the terrestrial ones it is impossible to speak of it as a definite central 
organ. In the marine forms, e.g. Gunda, it is highly developed, and 
consists of a large posterior, motor, transverse commissure, and a large 
anterior sensory commissure, the two being connected together by a 
sensori-motor commissure. After dealing with its position, the 
author passes to the Peripheral portion. The concentric arrangement 
of this in the Polyclades has been already referred to. As before, 
Tristomum presents the closest resemblance to that group, but certain 
changes have been effected, in consequence of the development of the 
ventral sucker, and there has been a reduction of the nerves at the 
anterior end of the body. In Pleurocotyle and Distomum little but the 
two longitudinal nerves have been preserved, and the commissural 
system would seem to have completely disappeared. In Amphilina 
the longitudinal trunks pass into one another; in the Tniade the 

‘branches for the suckers are still retained; and the Tetrarhynchi 
have special paired nerves, which pass to the proboscis ; no commis- 
sural fibres have as yet been detected in the Cestoda. 

Along the other line of development the central nervous system 


o 2 


196 SUMMARY OF CURRENT RESEARCHES RELATING TO 


takes on an arrangement which strikingly calls to mind those found 
in the higher segmented forms ; in consequence of the reduction of 
the lateral portions of the body and the simplification of the digestive 
and generative systems, the anterior and lateral nerve-trunks, as com- 
pared with the longitudinal trunks, have become quite inconspicuous ; 
and in many cases the same fate is reserved for the brain. 

The fresh-water Triclades come nearest to the Polyclades, but 
the longitudinal trunks unite posteriorly. The land forms, as repre- 
sented by Rhynchodesmus, present us with an arrangement in which the 
brain is nothing more than a somewhat well-developed portion of the 
longitudinal trunks with transverse commissures somewhat thicker 
than in the other parts of the body. The regular arrangement of the 
peripheral portion is best seen in the marine Triclades, Gunda 
having longitudinal trunks which, at perfectly regular distances, are 
connected by simple unbranched commissures, and, so far as seg- 
ments can be made out at all, there is a transverse commissure for each 
segment. The homology of this system is fully discussed. 

The mesenchymatous nervous system consists, in the Polyclades, 
of a fine network of nervous substance which is closely applied to 
the ventral and dorsal muscular layers; the meshes are generally 
polygonal, and the system is best developed in the region of the 
sucker. In the terrestrial Triclades the meshes are generally quad- 
rangular ; in the Trematoda the system is best developed in connection 
with the large ventral sucker, and ganglion-cells of considerable size 
may here and there be detected in it. Among the Cestoda Pleurocotyle 
has the plexus largely developed near the proboscis. 

No sensory organs, other than eyes, have been detected in the 
Platyhelminthes ; a large number of these are always to be found in 


the Polyclades, in the Trematoda they are less numerous, and in the) 


Cestoda they are either absent or are confined to the free-living 
stages. In most of the fresh-water and terrestrial Triclades two are 
alone found. In all cases there is presented a marked similarity of 
structure; optic cells, formed from the ends of the optic nerve, pig- 
ment-cups, and a crystalline body can always be made out. 

No complete series of observations have been made by the author 
on either the Rhabdoccela or the Nemertinea, 

The nervous system of the Triclades, the more general characters 
of which have already been pointed out, is dealt with in detail; in 
treating of the fresh-water forms the author has especially studied 
Planaria torva, and he finds himself in essential agreement with Graff, 
Kennel, and the Hertwigs. 

In dealing with the land forms he has the advantage of Moseley’s 
investigations into the land Planarians of Ceylon; a study which, he 
says, he has daily learnt to value more and more, though that author 
has called the nervous the primitive vascular system. This he 
regards as an error of interpretation which has been corrected by 
others, though the details have not been essentially altered. 

Gunda has been the chief example of the marine forms, and the 
author has been able to distinguish in it a motor portion which is 
formed by two ventral enlargements, from which there arise the anterior 


+ 
) 
4 
a 
a 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 197 


and posterior longitudinal nerves, and which are connected by motor 
transverse commissures. The sensory swellings are more dorsal and 
anterior in position; they give off the sensory nerves, and are likewise 
connected by commissures. Between these two sets there is a sensori- 
motor commissure. Histological structure no less than anatomical 
arrangement reveals the higher grade of development seen in the 
marine as compared with the other forms; the sensory are distin- 
guished from the motor nerves by being invested in a continuous layer 
of ganglionic cells. 


Structure of Gunda segmentata, and the Relationships of the 
Platyhelminthes with‘the Celenterata and Hirudinea.*— Dr. Arnold 
Lang commences by revising the classification of the lower Platyhel- 
minthes: he would drop the term Turbellaria, and adopt in its place 
three orders, each of them the equivalent of the Trematoda, Cestoda, 
‘or Nemertinea; the dendrocelous Turbellaria are either monogono- 
porous, or digonoporous, and for them he proposes the terms of 
Polyclades and Triclades, while the third order would be called the 
Rhabdoccela. 

Gunda segmentata is a delicate marine Planarian about 6 mm. long, 
and very active ; after giving a technical description of the species, the 
author passes to its epithelial layer, some of the cells of which are 
filled with the small characteristic rods, while others, on the ventral 
side, form a zone, which is broadest at the anterior end of the body; 
these attaching cells project considerably beyond the rest, and their 
free surface is roughened. The enteric system receives the name of 
the ccelenteric apparatus, inasmuch as the author is convinced that it 
is the homologue of the ccelenteric apparatus of the Coelenterata, and 
of the enteron and ccelom of the Enteroccela. In all essential points it 
_ agrees with that of the other Triclades; the mouth leads into the 
so-called proboscis cavity, from the walls of which are developed 
muscular folds which project into the cavity, and form the proboscis, 
in the fashion of a diaphragm. The cavity communicates by an orifice 
with another cavity, which is not, as is the former, lined by ectoderm, 
but by endoderm; from this there are given off the branches of the 
intestine, the anterior of which lies in the middle line, and ends 
blindly at the anterior end of the body. The two lateral primary 
branches lie close to the sides of the proboscis-sheath, and end 
blindly at the hinder end of the body; from these three primary 
branches are given off secondary diverticula, the ccelomic diverticula 
of the enteron; these agree in all essential points with the paired 
cavities of the enterocele of higher forms; they are generally 
unbranched, or are forked at their peripheral ends. There is no 
special musculature for the walls of the intestine; in the enteric cells 
we may sometimes see large vacuoles during life; these are called 
the excretory vacuoles. If we compare the above account with the 
arrangements which obtain in the Cienophora, we find there that 
the so-called stomach is lined with ectoderm, and is provided with 
glandular ridges, that the succeeding cavity is lined by endoderm, 


* MT. Zool. Stat. Neapel, iii. (1881) pp. 187-252 (3 pls.). 


198 SUMMARY OF CURRENT RESEARCHES RELATING TO 


and that from the funnel there arise the gastro-vascular canals, in 
the form of paired ones which pass off laterally and branch, and an 
unpaired one which passes to the aboral pole, and there opens; on 
the other hand, the unpaired branch in G'unda only opens to the 
exterior in an early stage. 

The Polyclades, like the Ctenophora, are hermaphrodite ; and in 
both groups the generative products arise in close relation to the 
branches of the enteron; Chun has described them as having, in 
the Ctenophora, their origin in the ctenophoral vessels, that is to say, 
from the endoderm; in the Triclades they are developed from the 
enteric epithelium, so that the homology would appear to be complete. 

The excretory organs of the Ctenophora are regarded as being 
represented by those pores by means of which the branches of the 
vessel of the funnel are brought into relation with the outer world ; 
in Gunda it consists of large canals, which anastomose with one 
another, and of a number of fine excretory capillaries which are 
considerably branched, but which do not anastomose. The large 
canals here and there give off large branches to the dorsal surface 
of the body without opening into contractile vesicles. Throughout 
the whole body of the animal there are scattered a number of 
smaller or larger vacuoles, which have a considerable resemblance to 
the contractile vesicles of the Infusoria. These vacuoles are not 
arranged irregularly, but are united into small groups, and when one 
of them is examined, we see that it is supplied by a branch from the 
excretory capillaries, and there is a ciliated band between the 
vacuoles. A fact, to which the author attaches much importance, is 
the presence of a large number of ciliated infundibula in and on the 
epithelium of the branches of the enteron. The vacuoles which 
surround the funnel cannot be distinguished from those which are 
found in the enteric cells; the protoplasm of the ciliated funnel is 
the plasma of an enteric cell, and the funnel is a hollowed endodermic 
cell, ciliated within. The homology between these structures and 
the protoplasmic networks to which they give rise, with the inter- 
cellular lymphatic plexus of Fraipont and Francotte, and the sub- 
cutaneous nerve-plexus found by Ihering in Graffilla muricola is 
insisted on, and it is found that, taking all the characters into con- 
sideration, they must be regarded as being formed on the same type 
as those of the Coelenterata. 

The musculature of the Polyclades arises from the four primitive 
cells of the mesenchyma; the cells which are to become muscular 
fibres are arranged in layers under the epithelium, and their arrange- 
ment, like the mode of locomotion, is different to that which is seen 
in the Coelenterata, but it is to be explained as due to their creeping 
mode of life, which demands a more regular distribution of the fibres, 
and a greater development of the superficial muscles. 

Our space will not allow us to follow the author into the com- 
parisons which he institutes between Gunda and the fresh-water 
Triclades, or the Hirudinea; he finds, however, that the Leeches are 
closely allied to Gunda ; and dealing with Trochosphera, he points out 
that all larvee of its type are only provided with organs which are, 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 199 


physiologically, most necessary to it; by means of these partly 
provisional organs, the larva seeks its food, and the material for 
afterwards developing its body; in other words, the trochosphere 
does not represent the whole body of a Platyhelminth, but merely 
the cephalic portion of Gunda, with a fresh structure, the anal 
segment. 

Echinodermata. 


Nervous System of the Ophiuroidea.*—N. Apostolides, who 
_has already} examined and described the circulatory and respiratory 
organs of this little-studied group, says that the circum-oral nerve- 
ring is contained in a “ perineural” space which forms part of the 
body-cavity, and communicates with the general body-cavity at the 
point of entrance of the radial nerves into the arm; the space is 
triangular in transverse section, and is bounded on the outer side 
by the second discoid ossicle of the skeleton, and above and below 
by two membranes which originate in the point of union of the 
stomach and cesophagus, and are inserted on the ossicle. The nerve- 
ring itself forms a vertically flattened band. The radial nerves pass 
off from it horizontally, each traversing the foramen in the second 
discoid ossicle; each then turns upwards as far as the ventral plate, 
when it again becomes horizontal and then traverses the furrow of 
the arm. The annular canal of the water-vascular system and its 
branches lie outside the corresponding parts of the nervous system. 
Histologically, the nerve-band consists of two distinct tissues, the one 
ventral, consisting of brown cells with large nuclei and not coloured 
by picrocarmine ; they have been wrongly regarded by most writers 
as constituting the essentially nervous element, but they resemble 
rather the pigment-cells of Vertebrata. ‘The dorsal portion of the 
band is the true nervous part; it forms a very small portion of the 
whole band, and lies in a groove on its superior aspect; it consists 
of extremely delicate fibrils, between which pale bipolar cells lie 
scattered, not aggregated into ganglia. 

The radial nerves exhibit certain dilatations opposite to intervals 
between the ossicles, but they are composed of the same non-nervous 
matter as that of which the ventral part of the ring consists. No 
branches are given off by the central ring, but the radial nerves 
give off from their origin a pair of nerves, the upper one of which 
goes towards the first tentacle and, when near it, divides; the two 
twigs thus formed course round the end of the tentacle and meet on 
the opposite side of it. The exact distribution of the nerve in the 
walls of the tentacle is unknown. The lower of the branches of the 
radii goes towards the muscles which lie between the angles of the 
mouth. Two similar pairs of nerves are given off by the radial 
nerve before it reaches the arm and another pair within the arm, 
all having the same distribution as the first pair. 

American Comatule.{—In his preliminary report on these forms 
Mr. P. H. Carpenter states that he thinks he has discovered as many 

* Comptes Rendus, xcii. (1881) pp. 1424-6. 


+ See this Journal, i. (1881) p. 466. 
t Bull. Mus. Comp. Zool. Camb., ix., No. 4 (1881) 20 pp. (1 pl.). 


200 SUMMARY OF CURRENT RESEARCHES RELATING TO 


as forty new species in the collections dredged in the Gulf of Mexico 
and the Caribbean Sea. Nearly all were obtained from depths less 
than 200 fathoms ; new and very singular types were obtained on the 
three occasions when Comatule were brought up from more than 
300 fathoms. As very similar conclusions are to be drawn from the 
‘Challenger’ collection, it seems that Comatule are essentially 
inhabitants of shallow water. When we compare the two collections 
it is interesting to see how they supplement one another. Ten-armed 
forms abound in the Caribbean, while in the eastern seas the majority 
have the rays always dividing, in some cases as many as seven 
times. The characters of several little-known species are discussed, 
and Antedon spinifera n.sp., and Actinometra pulchella Pourtalés are 
described in detail, Attention is again directed by the author to the 
characters which distinguish the genera Antedon and Actinometra, and 
these are usefully summarized in a table. 

Two Pentacrinoid forms were found entangled in the arm of 
Act. meridionalis, and are presumably the young of that species; if 
so, they are probably the first Pentacrinoid Actinometre that have 
been observed: a study of these specimens and of young Antedons 
leads to the belief that the late appearance, as a whole, of the basal 
pinnules is a “ marked developmental character among the Comatule.” 
This is of interest in connection with Mr. Carpenter’s account of a 
new genus Atelecrinus, in which the basal circlet is complete in the 
adult as it is insome Pentacrini, and the earlier stages of Pentacrinoid 
larvee. In the characters of its calyx this new genus retains per- 
manently larval characters ; so, too, there is an absence of pinnules 
from the lower part of the arm. Ant. cubensis with the new species 
A, balanoides will belong to this genus. 


Coelenterata. 


Characters of Stinging-cells of Celenterata.*—Dr. C. Chun 
recalls the fact that late investigations have directed attention to 
the nature of the processes which connect the stinging-cell with 
the supporting lamella (“mesoderm”); Claus has regarded them as 
muscular fibres, and the brothers Hertwig as nervous structures. 
If we examine their mode of termination we find that they may 
or may not pass into the ectodermal longitudinal muscles of the 
tentacles. Observations tending to the conclusion that the processes 
in question are representatives of muscles are confirmed by the exami- 
nation of Physalia, for in this Siphonophore it is to be observed that 
hundreds of muscular lamelle arise, with extraordinary regularity, from 
the muscular band which passes to some of the filaments; the vessel 
running through the middle of the band gives off, under each battery 
of stinging-cells, a widening branch, the endodermal cells of which 
are remarkably increased in size beneath the battery. In other 
words, we find in Physalia a mesoderm well developed and traversed 
by cellular elements. The rounded nettle-capsules of each battery 
may be small or superficial, or larger and deeper. The stalks of the 


* Zool. Anzeig., iv. (1881) pp. 646-50. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 201 


small stinging-cells are distinctly transversely striated ; in the case-of 
the larger cells we find that the stalk contains in its centre large oval 
nuclei, the contractile substance is broken up into 8-12 transversely 
striated fibrils placed at regular distances from one another; at the 
level of the capsule these branch dichotomously, and at the end where 
the cnidocil is placed we find a large number of fine contractile fibres 
converging in a regular manner, and at regular distances. 

Now that the connection of muscles with the stinging-cells has 
been made certain, it is easy to see what is the real nature of the 
pressure on the wall of the capsule, which has been universally 
recognized as necessary for the protrusion of the spiral filament, 
When the network of fibrils contracts there must be a certain pressure 
on the wall; where this network is absent, the contraction of the 
stalk must press the capsule against the tissues which underlie it; 
and both causes may act, as in Physalia, at the same time. As to 
the irritability of the muscles it is to be noted that the necessary 
connection of the muscular stalk with nervous elements has so far 
been worked out by Chun in Physalia that ganglionic cells have been 
there observed, and that sensory hairs are always richly developed in 
the region of the urticating batteries. 

Morphologically, the stinging-cells appear to represent not glands, 
the secretion of which forms the capsule, but epithelio-muscular 
cells. 


Development of the Celenterata.*—In these comparative embry- 
ological studies E. Metschnikoff considers the formation of the endo- 
derm in the Geryonida, and the development of the Cunina parasitic 
in Carmarina. 

In dealing with the former, the author refers to the doubts expressed 
by Professor Haeckel as to the reality of the delamination method 
of the formation of the gastrula; and relates how in Carmarina fungi- 
- formis he was able, at the stage of the formation of thirty-two blasto- 
meres, to separate the finely granular ectoplasm from the wide-meshed 
endoplasm; most of the cells were seen to be dividing, and this 
process of division was best marked in the nuclear spindle. Those 
that divided radially gave rise to new blastodermal elements, while 
others which divided tangentially separated the endoderm from the 
ectoderm. In a second form, Liriope eurybia, the delamination-process 
was most clearly observed, some of the blastodermal cells grew deep 
into the cleavage cavity, the nuclei were seen to be dividing; when 
the cell protoplasm was constricted the ectoplasm was almost ex- 
clusively found in the peripheral and the endoplasm in the central 
segment. This process was succeeded by the formation of a separate 
endodermal layer and then of a diblastula. 

Dealing with the Cunina parasitic on Carmarina the author 
examines the accounts of the formation of the gastrula in the Hydro- 
meduse ; and in giving a description of his own observations states 
that the youngest form examined by him formed a small white dot 
on the margin of the umbrella of Carmarina fungiformis ; under the 


* Zeitschr. f. wiss, Zool., xxxvi. (1881) pp. 433-44 (1 pl.), _. 


202 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Microscope it was seen to be a rhizopod-like organism with a rounded 
cap ; that is to say, the larva proper contained a colossal amceboid cell 
and a bell-shaped covering of flagellated epithelium. The large cell 
gave off a number of homogeneous processes, many of which branched 
or were flattened out at their free ends. Within there was a large 
nucleus, closely resembling the central capsule of many Radiolaria, 
and this was invested in an elastic membrane, and had finely granular 
contents. This large cell is the body which was spoken of by 
Uljanin as the finely granular mass within the gastric cavity. The 
further stages of development are characterized by the overgrowth of 
the colossal amceboid cells by the flagellated cells, and the con- 
sequent formation of the oviform larva, which Uljanin regards as 
the starting-point of his invaginate archigastrula; but the author 
points out that there is in it no round blastopore, but only a fine 
slit; this does not serve for the ingestion of nutriment but only 
as a means of passage for the pseudopodia of the enclosed colossal 
cell. The larve, increasing in size, become elongated, and often 
triangular in form; the ectoderm is sharply separated from the 
endoderm, and consists of a single layer of delicate flagellated cells ; 
while the endoderm forms a single layer of cylindrical-flattened 
cells. 

Gemmation commences even at this stage, a longitudinal section 
revealing a diminution of the two germinal layers at the point where 
the mouth of the first Medusa appears later on; a well-marked pro- 
jection at the oral pole forms the proboscis of the first Medusa-bud. 
In later stages we find that the colossal cell is long persistent ; the 
first sign of degeneration would appear to be the appearance of 
several—perhaps renal—concretions; later on this degeneration 
becomes gradually complete. 

The author is of opinion that the whole life-history of this 
parasitic Medusa presents a series of secondary adaptations, which 
are in causal connection with the parasitic habit; the alternation of 
generations is of a secondary nature, and the asexual generation is 
characterized by the loss of the genital organs and of a number of 
the other organs of a Medusa. 


Nervous System of Hydroid Polyps.*—C. F. Jickeli states that 
he has discovered nervous elements in these, the only Coelenterata in 
which they have not yet been observed. In the arms of the hydranths 
of Eudendrium, he found between the flat ectodermal cells and the 
longitudinal muscular fibres, branched cells, whence processes pass off 
to a number of urticating cells, or become lost between the muscular 
fibres; there is also a direct connection between the ganglionic cells. 
He asserts the existence of a nervous plexus which is continued 
forwards to the hypostome, and which extends also into the hydro- 
phyton. Near the circlet of glandular cells at the base of the 
hydranths there is a larger collection of ganglia; but the connection 
by nerve-fibres between the two was not made out. The nervous 
system would appear to be confined to the ectoderm. 


* Zool, Anzeig., v. (1881) pp. 43-4, 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 203 


Remarkable Organ in Eudendrium ramosum.*— When engaged 
in his investigations into the mode of origin of the generative 
products of this hydroid, Dr. A, Weismann observed remarkable 
outgrowths on the head of the hydranth, of which, at first, he took no 
especial notice, as he regarded them as pathological products. They 
are horn-shaped stout processes growing out laterally from the head 
of the polyp; in form, though not in dimensions, they resemble a 
tentacle, with the exception that they are not thinner, but, as a rule, 
swollen at their free ends; they are formed by the two body-layers, 
and contain a continuation of the body-cavity; they are not found 
on all the hydranths of a colony, and this might lead us to think 
that they are degenerated structures; that, however, they are not 
degenerated gonophores is shown by the fact that, while all gono- 
phores arise below the circlet of tentacles, or in the upper half of 
the hydranth, these are always developed below the hydranth ; again, 
their structure shows that they have a definite function, they are 
actively motile, have a well-developed muscular layer, and are so 
remarkably well provided with urticating organs that they might be 
spoken of as cnidophores. 

If we enter into the details of their structure, we find that the 
ectoderm only differs from that of the hydranth in its much richer 
supply of urticating organs; while there is nothing remarkable in 
the supporting lamella, there are, in addition to the epithelial cells of 
the endoderm, subepithelial cells lymg on the supporting membrane 
and giving origin to circularly arranged muscular fibres: as yet 
circular muscles have only been observed in Tubularia among the 
Hydroid Polyps. In Hudendrium the circular muscular layer of the 
cnidophores is strongly déveloped and consists of very fine long fibres, 
which frequently exhibit a delicate transverse striation. After this 
description it can hardly be doubted that we have to deal with an 
offensive organ ; the power of active movement, and the notable supply 
of stinging organs of colossal size sufficiently demonstrate the 
correctness of this view of their function. 

The cnidophores always arise from a circular but indistinct 
wall of ectoderm, which is separated off by a circular groove from the 
wall of the stalk; this groove may be known as the glandular ring, 
and the wall as the urticating wall. In the region of the former the 
ectoderm cells are in one layer only, or, the glandular cells reach to 
the surface, 

Viewed morphologically, the cnidophores are seen to be processes 
of the body-wall; in their earliest stages they are blunt, broad, solid 
processes of the urticating wall developed by a thickening of the 
ectoderm. In the next stage they contain an endodermal process, and 
thence to the complete condition there is every kind of intermediate 
stage. It is important to note that they only arise on developed 
hydranths, for this shows that they are, phylogenetically, relatively 
young organs. Their presence on some hydranths only presents 
some difficulties, and we can only suppose, till they shall have been 
studied during life, that they are developed as a protection against 


* MT. Zool. Stat. Neapel, iii. (1881) pp. 1-14 (1 pl.) 


204 SUMMARY OF CURRENT RESEARCHES RELATING TO 


some special kind of enemy. If it be true that they are not found on 
other species of the genus, we shall have another proof of their late 
development in time ; their great size has prevented their develop- 
ment in large numbers on the same person, and may be the explana- 
tion of their asymmetrical character. No organ known in any other 
Ccelenterate can be compared with them, with the exception of the 
nematophores of the Plumularida, in which there is a process con- 
tinued from the endoderm, though one that is only feebly developed. 
Three kinds of offensive organs seem, therefore, to have arisen inde- 
pendently of one another, for in the Hydractinide they are repre- 
sented by the so-called spiral zooids. 


Siphonophora of the Bay of Naples.*—M. Bedot finds that the 
Bay of Naples is one of the richest of all parts of the Mediterranean 
for these interesting forms; in one season he found 17 species, and 
altogether he knows of 19; all the families of the order are repre- 
sented, and Physophora philippii, Forskalia contorta, Halistemma 
rubrum, Praya diphyes, and Diphyes quadrivalvis are very abundant. 
Of the last-named form the author had some specimens 60 em. long, 
and he once observed an abnormal example, with three swimming- 
bells. 


Ctenophora of the Bay of Naples.{—A very complete abstract of 
this monograph by the author, Dr. C. Chun, will be found at pp. 193-5, 
and 212-26 of Part 1 of the ‘ Zoologischer Jahresbericht’ for 1880. 


Protozoa. 


Symbiosis of Lower Animals with Plants.— Yellow Cells of 
Radiolarians and Celenterates.—See infra, Borany, Algw. 


New sub-class of Infusoria—(Pulsatoria).|—Three years ago 
Mr. P. Geddes described § some curious cells which occur in large 
numbers in the mesoderm of the Planarian Convoluta schulzii. The 
cells are a little smaller than the red blood-corpuscles of the Frog, 
are nearly in the form of a slightly curved pear, and have a large 
central vacuole, filled with fluid. On the wall of this cavity, and 
towards the more convex side of the cell, almost parallel with its 
principal axis, there is a row of homogeneous and transparent fibrillze 
which are inserted at their upper and lower extremities in the ordi- 
nary protoplasm of which the other parts of the cell is composed. 
This differentiation into a granular and fibrillar part is comparable 
to that which takes place in the embryonal muscular cells of the 
Tadpole, and recalls somewhat the structure described by Lankester 
in the heart of Appendicularia. If these cells are examined 
free in sea-water it is seen that they are in a state of rhythmical 
contraction, the rapidity and vigour of which are equally surprising, 
the most active pulsating from 100 to 180 times per minute; each 


* MT. Zool. Stat. Neapel, iii. (1881) pp. 121-3. 

+ Fauna u. Flora des Golfes von Neapel, Mon. I. pp. xviii. and 313 (22 
figs. and 18 pls.). 

t Comptes Rendus, xciii. (1881) pp. 1085-7. 

§ Proc. Roy, Soc., xxviii. (1879) p. 449. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 205 


time the principal axis becomes more strongly curved, and the cell 
shorter and broader. This change of form depends exclusively on 
the contraction of the inner fibres, the other parts of the cell remain- 
ing quite passive. The movements of the cells soon begin to slacken, 
become irregular and feeble, finally cease, and the cell bursts. Its 
protoplasm soon perishes, but the fibres resist for a longer time the 
action of the water, and even exhibit a trace of contractility like 
dying cilia. 

Numerous observations have convinced Mr. Geddes that these 
cells are in reality parasites. Other species of Planarians possess 
nothing like them. The delicacy of their protoplasm distinguishes 
them from the true tissue of the Convoluta. Moreover, they do not 
form tissue, and have no definite disposition. Regarded as parasites, 
their structure, apparently so abnormal, is readily derived from the 
type of ordinary Infusoria by the suppression of the cilia (which 
would not be available for locomotion among the cells of the meso- 
derm) and the differentiation of the contractile vesicle. 

This differentiation is certainly very remarkable from every point 
of view when we consider the relatively enormous size of the vacuole, 
the development of the contractile fibres which limit it, or the rapidity 
of their contraction. 

The author proposes to call this Infusorian Pulsatella convolute, 
and as it is so distinct from either Suctoria, Ciliata, or Flagellata, to 
create for it a fourth sub-class Pulsatoria. 


Skeleton of the Radiolaria.*—Professor Biitschli deals especially 
with the Cyrtida, having had the advantage of studying a number of 
fossil specimens from Barbadoes. He commences with a study of 
Colothamnus (?) davidoffii n. sp., a Phoeodarian in which the skeleton 
is as much as 14 cm. in diameter. Examined with the naked eye, 
it is seen to be a (marine) organism, stellate in form, with sixteen 
relatively long rays, which appear to arise from a common centre. 
These rays are skeletal parts, and are, with the centre, imbedded in 
a common gelatinous mass. Belonging to Haeckel’s family Ccelo- 
dendrida, its exact generic position must still remain a matter for 
discussion. The central portion is formed of two separate valves, 
which resemble one another in their structure, though not in their 
form. The details of their characters and of their connection with 
the rays is given. 

The structure and relations of the Acanthodesmida, Zygocyrtida, 
and Cyrtida (Cricoidea: Biitschli) are then dealt with in detail; and 
the author concludes by pointing out that he cannot regard as natural 
Haeckel’s division of the Cyrtida into Mono-, Di-, and Sticho-cyrtida. 
He can only distinguish two separate phyla, but he is careful to point 
out that our knowledge of these forms is at present very slight. 


Recent Researches on the Heliozoa.—L. Maggi f has observed on 
a Spirogyra a form belonging to Cienkowski’s genus Nuclearia, and, 


* Zeitschr. f. wiss. Zool., xxxvi. (1881) pp. 485-540 (8 pls.). 
+ Rendic. R. Istit. Lomb., xiii. (1880) fase. 20. Cf. Zool. Jahresher. Neapel 
for 1880, i. pp. 154-5. 


206 SUMMARY OF CURRENT RESEARCHES RELATING TO 


considering it, on account of its having two nuclei, to be a new species, 
assigns toit the name N. duplex. This species undergoes encystation 
occasionally, like the other Nuclearie, and during the process Maggi 
saw the two nuclei increase by fission to four. Then followed the 
division of the envelope of the cyst, in such a way that one of the por- 
tions into which it divided enclosed the old nuclei, and the other the 
newly-formed nuclei. This bi-nucleate Nuclearia the author believes 
himself justified in regarding as exhibiting a most important phylo- 
genetic step towards the bi-nucleate condition shown by the fertilized 
ovum in the simultaneous occurrence of a male and a female nucleus, 
and finds the explanation of this doubly-nucleate developmental stage 
of the Metazoan ovum to lie in the existence of a phylogenetic 
bi-nucleate Protozoan predecessor of the character here described. 

G. Cattaneo,* after a short historical survey of the investigations 
which have been made among the Heliozoa, describes his observations 
on Acanthocystis flava Greef, made on a single specimen in the course 
of two mornings. As might have been expected, he has but few 
facts to show, although the conclusions which he strives to draw 
from them are none the less far-reaching. He cannot regard the 
external, vitreous, colourless protoplasmic zone of A. flava, which 
has been described as ectosarc by various authors, as such, but con- 
siders it to be what he terms mesoplasm. ‘The reasons for this opinion 
_ are that it contains the contractile vacuole, and sends out the fine 
pseudopodia which serve only as organs of prehension, these being the 
characters of the mesoplasm, as elaborated by Maggi in the case of 
Podostoma, &c. The ectoplasm proper of the present form, Acantho- 
cystis, is said to be developed into the silicious skeleton, which cannot 
be regarded as a product of excretion of what is usually called meso- 

lasm, The author finds a confirmation of this view in the relations 
of the parts of the so-called chlamydophorous Heliozoa, in which the 
ectoplasm proper is still to be found in the condition of an external 
envelope, while further on in the developmental history of Arcella 
vulgaris, as described by him, he finds that the ectoplasm which is 
present in the young stages developes later into the shell.t The 
author, of course, extends this view as to the nature of the investing 
skeleton to all the Heliozoa which have skeletons. 

Cattaneo also states that he has observed the following. The 
simple central nucleus, said to possess a deeper brown coloration 
than the investing entosarec, was divided by a constriction after its 
nucleolus had become double. One half of the nucleus remained in 
the centre, while the other wandered to the surface of the entoplasm. 
Brown granules then became developed in numbers, and were finally 
scattered through the entosarec; they are regarded by the author as 
spores. From this observation he believes it necessary to doubt the 
occurrence of simple fission under any form in such highly-developed 

* Atti Soc. Ital. Sci. Nat., xxii. (1880) p. 46 (1 pl.). Cf. Zool. Jahresber. 
Neapel for 1880, i. p. 155. 

+ Professor O. Biitschli remarks (Zool. Jahresber. Neapel for 1880, i. p. 155) 
of this observation, that it justifies an opinion expressed by himself in Zool. 


Jahresber. Neapel for 1879, as to the probability of an origin of this kind for the 
shell of Arcella. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 207 


Protozoa as the Heliozoa. In them reproduction takes place by 
polysporogony; in the Thecolobosa also the ordinary method of 
reproduction is the generation of numerous germs in the entoplasm. 
He endeavours to derive the buds observed by R. Hertwig in Acan- 
thocystis aculeata from such internal spores as these whose existence 
he assumes. Naturally, the formation of swarm-spores observed in 
Actinophrys and Actinospherium by Greef and Archer appear to him 
to support his explanation. He explains the feeble phenomena of 
motion exhibited by Acanthocystis flava as not caused by the pseudo- 
podia, but as due to the mobility of the skeletal elements and to 
slight dislocations of the surface of the body. 


Dimorpha mutans.*—Dr. A. Gruber regards this form as being 
intermediate between the Flagellata and the Heliozoa; he points out 
that the systematic position of the former has been a matter of much 
difficulty, but that Stein is probably right in associating them 
especially with the Infusoria. With regard to their mode of locomo- 
tion, it may be pointed out that in the Protozoa we may have a 
streaming of protoplasm, the action of flagella, or ciliary movement ; 
there are no fundamental differences between these modes, and in 
some cases more than one is to be seen in one individual; among 
_ these is the organism here described. At one moment appearing to 
be an Ameba radiosa, it suddenly seemed to shoot out a long flagellum 
on one side; the body then elongated and became oviform, while the 
pseudopodia began to shorten: two flagella were now seen. After 
moving about, it suddenly stopped, became spherical, and gave off 
radially fine pseudopodia, so that it looked like a Heliozoon. The 
cycle of change was again repeated, and was observed in numerous 
specimens. 

The swimming movement is always connected with a rolling 
round the long axis, which renders observation somewhat difficult ; 
it was, however, possible to see that the margin of the body was often 
quite smooth, so that it resembled a monad; the protoplasm at the 
anterior end is then much clearer and free from granules, while the 
middle portion is dark and contains larger crystalline corpuscles. 
The nutrient material is collected at the hinder end of the body. 
There are always two flagella, arising near one another at the anterior 
blunted pole. No mouth could be seen, and the dark protoplasm 
completely obscured the nucleus. There is a large contractile 
vacuole, but there is no cuticle. The pseudopodia would appear to 
be what Engelmann has called myopodia, or to present a fibrillar 
structure; when a spore of an alga is seized between two pseudo- 
podia, it is almost immediately killed; it is carried to the periphery 
of the mass of the body and is seized by a broad protoplasmic process, 
just as in an Ameeba ; as this may take place at two points of the body 
simultaneously, it is clear that there is no part specially set apart for 
the ingestion of nutriment. In four hours digestion is completed. 
The general protoplasm is soft and not very consistent. On the 
whole Dimorpha presents the characters of a true Heliozoon, but in 


* Zeitschr. f. wiss. Zool., xxxvi, (1881) pp. 445-59 (1 pl.) 


208 SUMMARY OF CURRENT RESEARCHES RELATING TO 


addition, the two flagella never completely disappear, however much 
they may be hidden from view; nor is the body perfectly round. 
The study of its developmental history was, unfortunately, only 
incompletely carried out. 

The author concludes by discussing the doctrine of Bergh that 
the Cilio-flagellata are the lowest forms; to this he cannot give his 
adhesion, believing rather that the Rhizopoda stand nearest to formless 
plasmodia. 


Contributions to the Knowledge of the Amebe.*—Dr. A. Gruber 
points out that Auerbach,f starting from the assumption that a mem- 
branous boundary was a necessary attribute of a cell, set up a theory, 
according to which the Amcebe also, as unicellular creatures, had a 
membranous envelope. This opinion was refuted by subsequent 
naturalists, principally Greeff,t but with its overthrow some forms of 
Amebe and many of the phenomena of their sarcode body, well known 
to Auerbach, although not quite rightly interpreted by him, seem to 
have been lost sight of. 

The existence of a fine layer of clear protoplasm round the 
Ameba body, which must be penetrated by the pseudopodia, is by 
no means an insignificant phenomenon, and the author therefore 
considers it useful to describe another Ameba of the same kind (A. 
tentaculata), and to reinvestigate Auerbach’s A. actinophora. 

1. Ameba tentaculata sp. n. was found in a small sea-water 
aquarium, the water and organisms being chiefly derived from the 
Frankfurt aquarium, but mixed with some from the Baltic and 
Mediterranean. 

It forms a little mass of very variable size, 0:03 mm. to 0:12 mm. 
In consequence of its greater refractive power, the body stands out 
luminously from the water, a property which in the protoplasm of all 
Rhizopoda goes hand-in-hand with greater viscosity. We find the 
rule confirmed here, for the protoplasm of A. tentaculata is, in fact, 
an extremely tenacious mass, in comparison with that of allied 
creatures. 

Under a power of 80 we can see no movement or change of form, 
and it is only with high and very high powers that we can recognize 
an Ameba in continual although sluggish change. 

Examined in the resting state, it has essentially the same form as 
A. verrucosa; i.e. the whole body is shrunk together, and covered 
with elevated knobs and deep folds which slowly change their form 
and position. 

In the interior the vital activity of the protoplasm is manifested 
by a streaming and trembling movement of the fine dark granules 
with which the sarcode is abundantly furnished. 

But while in A. verrucosa we miss true pseudopodia, both in the 
resting state and during flow, we are surprised here by seeing fine 


* Zeitschr. f. wiss. Zool., xxxvi. (1881) pp. 459-70 (1 pl.). See Ann. and 
Mag. Nat. Hist., ix. (1882) pp. 106-16 (1 pl. the use of which has been 
obligingly allowed us by the publishers). 

+ “ Ueber Einzelligkeit der Amében,” Zeitschr. f. wiss. Zool., Bd. vii. 

¢ Greeff, ‘ Ueber einige in der Erde lebenden Amében und andere Rhizopoden,’ 


be 


fs 


~ 


"ee * ce vA ‘ ; pane 
mame. 5 tn 6 ere Le 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 209 


protoplasmic filaments at different parts of the body. There are 
three processes of equal breadth throughout which stand out from the 
body, sometimes in one place, sometimes in another, and bend to and 
fro as if feeling about, often curved, but generally pretty straight. 
At first it seemed that these pseudopodia did not, as in other Amebe, 
spring from the protoplasmic body in the shape of fingers gradually 
becoming thinner, but that small conical elevations of the body served 
as their base, and that they rose from these with a distinctly marked 
separation. When they were very numerous they gave the Ameba a 
very peculiar appearance (PI. III. Fig. 1). 

With a Hartnack No. X. (or Seibert’s homogeneous immersion) 
the whole Amceba proved to be enveloped by a fine layer of denser 
substance, a membranaceous cortical layer which causes the periphery 
of all its humps and processes to appear distinctly double-contoured. 

Directly within this firmer envelope lies the soft internal sarcode- 
mass. Ifa pseudopodium is to be pushed forth, the enveloping layer 
must first be broken through. This, however, offers some resistance, 
and is consequently pushed out in a conical form. An aperture is 
broken through at the apex of the cone, and the sarcode issues in the 
form of a thin filament (Fig. 8). The retraction of the pseudopodium 
was very distinctly observed, after which a new one frequently issued 
from the same cone. 

The pseudopodial cones have a very constant form, and although 
they can obliterate themselves again completely, this does not always 
take place after the retraction of the pseudopodium; but very 
frequently the elevation remains, and a small crater seems to have 
been formed where the pseudopodium was emitted (Fig. 2k). One 
specimen had many cones, but all without processes (Fig. 4 r), 
nevertheless they persisted without alteration for a considerable 
time. 

Whether the pseudopodia act as tactile organs or bring in food, 
cannot be definitely stated. The former, however, appears to be more 
probable, for in the interior are nutritive materials, such as diatoms, 
alge, &c., much too large to be capable of penetrating through the 
narrow aperture of the cone. 

At any rate the animal, notwithstanding its firmer enveloping 
layer, is able to take in solid materials. Moreover, we know very 
nearly allied forms such as A. verrucosa, which are destitute of these 
organs, and nevertheless take in such nutritive bodies. Sometimes it 
appeared as if a slow locomotion was effected by means of the 
pseudopodia, but only to very inconsiderable distances. 

In advancing, A. tentaculata employs no special organ any more 
than its allies which possess a firm cortical layer. The humps and 
folds gradually disappear, the pseudopodia are for the most part 
drawn in, and with them the cones, and after the surface has become 
smooth, there commences a steady flow in one direction, exactly in 
the same manner as has long been known in A. verrucosa, although 
much slower. In the latter this stage was for a time regarded as 
forming a distinct species under the name of A. quadrilineata. 

The longitudinal folds which gave the name to the latter, and 

Ser. 2.—Vot. II. if 


210 SUMMARY OF CURRENT RESEARCHES RELATING TO 


which are produced by the strain on the tenacious outer layer acting 
in one direction, oecur here also (Figs. 5, 6, and 7). Along them we 
see the granules hastening forward in several streams, whilst a clear 
mass of protoplasm, free from granules, in constant flow, moves on 
before them. A remarkable-circumstance is that on the leading part 
of the body, pseudopodia with their cones frequently persist, and thus 
to a certain extent may act as extended feelers (Fig. 7). 

While at the end opposite to that which is pushing forward the 
double contour is distinctly preserved in the outer layer, it disappears 
entirely on the anterior part (Fig. 6), from which it seems that the first 
mentioned part of the body retains its toughness, whilst anteriorly 
all becomes in flux, i.e. the more fluid constituents collect there. 
Nevertheless, even these still have considerable density, as is proved 
by the pseudopodia and pseudopodial cones protruded from them, 
on which, however, no double contour is visible. Frequently a zone 
of clear protoplasm seems to surround the whole body, and then the 
double lines are no longer seen anywhere. 


EXPLANATION OF PLATE III. 


Fic. 1.—An Ameba tentaculata with many pseudopodia. 

Fie. 2.— Another, 0°12 mm. long, under a higher power (Hartnack eye-piece 
3, objective 10 immersion). It shows the cortical zone (7s), the pseudopodia 
(p s) on their cones, and at £ a cone of which the pseudopodium has been retracted 
(crater). 

Fig, 5.—A portion with three pseudopodia highly magnified. 

Fic. 4.—A specimen with a number of craters (4). 

Fic, 5.—A specimen in which the cortical zone is dissolved. 

Fie. 6.—A flowing A. tentaculata, in which the nucleus (x) is very distinctly 
visible. 

Fic. 7.—Another, in which three pseudopodia (ps) are still retained on the 
advancing part. 

Fic. 8A.—A pseudopodium with its cone. m, the soft interior mass; 7, the 
cortex ; p, the pseudopodium. : 

Fic, 88.—A pseudopodium in course of being retracted. 

Fie. 9.—An A. actinophora, with a distinct cortical layer (r s) and a tuft of 
pseudopodia at one end (Hartnack eye-piece 3, objective 7). 

Fic. 10.—Another, with few pseudopodia, distinctly showing how they break 
through the cortex. (Rather too large in proportion to the following figures.) 

Fic. 11.—The same example a short time afterwards. The cortex (7 s) is 
almost everywhere liquefied, and has become converted into a clear space (A); 
n, the nucleus which is distinctly visible in this state. 

Fic. 12,—The same, with the cortex completely dissolved ; v c, contractile 
vacuoles. 

Fic. 15.—The same, in slow flow in the direction indicated by the arrows; 
r s, the newly reconstituted cortex. 

Fie. 14.—Another example, in which the cortex has just become liquefied, 
but it is still retained at one spot together with two pseudopodia. 

Fie. 15.—An Ameba, in which the cortex has dissolved before two pseudo- 
podia (ps) were retracted. These became liquefied soon afterwards. In this 
an 

Fic. 16 the granular protoplasm is sharply separated from the hyaline 
sons. This, however, only lasts for a few moments to give place to the state 
in Fig. 12. , 

Fie. 17.—An Ameba, in which the liquefaction of the cortex has just com- 
menced on one side, treated with osmic acid. The cortex (r s) appears finely 
punctuate, as also the hyaline sarcode ; the nucleus at n. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 211 


Of a nucleus nothing is to be seen in the resting state when the 
folds obstruct the view of the interior. But if the Rhizopod begins 
to move when the body flattens, the nucleus becomes distinctly visible 
(n in the figures), as a little disk surrounded by a narrow border, as 
in most Amcebee. No contractile vacuole is present, a new proof of 
the still unexplained fact that this structure is wanting in the marine 
Rhizopoda. 

2. Ameba actinophora Auerbach is very small, measuring 0°03- 
0:04 mm., occurring pretty plentifully in all sorts of receptacles of 
water in the neighbourhood of Lindau. It is exceedingly suitable 
for the completion and elucidation of the previous observations. 

The first striking point is, that here also the protoplasm is 
distinctly surrounded by a double contour, the animal appearing as if 
covered by an envelope. The periphery is for the most part perfectly 
smooth, and only at one point does the animal extend a larger or 
smaller number of lobate pseudopodia. In this way the Ameba 
acquires delusively the appearance of a thalamophorous Rhizopod 
with a closely fitting thin carapace, from the orifice of which pro- 
cesses protrude (see Fig. 9). In this condition the protoplasm in 
the interior forms a tolerably compact mass, in which there are a 
number of rather strongly refractive granules. 

When the number of the pseudopodia is large, so that a whole 
tuft of them protrudes at once (Fig. 9), we see nothing of the cortical 
zone at their place of issue. It is otherwise when only two or three 
processes are pushed forth. The relations of the marginal layer 
are then quite distinctly visible, and we find that, just as in 
A. tentaculata, the cortex is pushed out into a cone at the apex of 
which the pseudopodium makes its way out. Here, therefore, the 
double contour is also produced by a more tenacious layer surround- 
ing the animal, which must be penetrated by the protoplasmic 
processes before they can issue (Fig. 14). Even in the previously 
described form, however, we saw that we have not to do with a per- 
sistent membranous structure, but that during the flow of the animal 
the cortical layer becomes amalgamated with the rest of the sarcode. 
This is much more distinctly observable in A. actinophora. Thus 
all at once we see how, as the animal changes its form, the pseudo- 
podia are at the same time nearly all retracted, the body becomes 
flattened, the cortical zone vanishes, and flows into a broad border of 
clear protoplasm, which surrounds the darker richly granular mass 
in the centre of the animal (Figs. 11 and 12 h). The latter often 
remains for some time sharply discriminated from the hyaline border 
(Fig. 17), but the boundary is soon obliterated, exactly as during 
the formation of an ordinary pseudopodium (Fig. 12). In this state 
the nucleus (n) also becomes distinctly visible, agreeing precisely in 
its structure with those of other Amebe. 

The melting of the fine cortical layer into the broad clear border 
does not take place with equal rapidity at all points, so that a part 
of the Ameba often appears sharply limited, whilst another is already 
surrounded by the clear space (Fig. 11 r,s). In Fig. 14, for example, 
is represented an A. diffluens, one side of which is already quite 


Pp 2 


212 SUMMARY OF CURRENT RESEARCHES RELATING TO 


liquefied, while on the other half the double contoured enveloping 
layer is still retained, and on it even two pseudopodial cones with 
the processes issuing from them are still visible. Fig. 15 is also 
instructive in another way. There the cortical layer has become 
fluid, and we see that the two pseudopodia which have persisted, 
consist of the same hyaline protoplasm as the clear border in which 
the cortical zone previously sharply separated from it (Fig. 14), has 
dissolved itself. In the first state, therefore, there would have been 
an envelope and an endoplasm enclosed by it, and from which the 
pseudopodia proceeded clearly distinguishable ; in the latter, both have 
become fused into one. Rapidly as the broad, scarcely visible border 
had formed, it can just as rapidly contract itself again; it shrinks 
to a certain extent together, until the narrow cortical layer again 
originates from it. 

In this way A. diffluens can continually change its aspect com- 
pletely in one or other of the modes described. Upon what law this 
power depends cannot be stated definitely ; very probably, however, 
different conditions of pressure come into play in the matter. With 
a centripetal pressure acting uniformly upon the whole periphery, the 
more fluid parts of the protoplasm are all pressed into the interior, 
and only the narrow membranaceous boundary remains. ‘This 
acquires a firmer consistence by contact with the water, and therefore 
at the points where pseudopodia issue, it is pushed aside by the 
latter. If the general pressure ceases, the more fluid constituents 
again come forth from the interior, dissolve the solidified cortical 
layer, and form the clear border. 

The best illustration of this explanation of the process is furnished 
by those cases in which a slow flowing forward of the Ameba in one 
direction is taking place (Fig. 14). On the advancing side the fluid 
constituents are pushed on in front; here all pressure has ceased 
whilst it acts upon the opposite side, where accordingly the cortical 
contours are quite distinctly to be seen. 

Auerbach had also observed this liquefaction into a disk as is 
shown by his Fig. 8, but he conceived of it as a phenomenon of 
expansion in which the cell-membrane also had to take part, but we 
know that no such membrane exists, and that the envelope is to be 
regarded only as a transitory concentration of the outermost layer of 
sarcode, and can at any time dissolve again (Fig. 11). 

Dealing with Cochliopodium pellucidum of Hertwig and Lesser, the 
envelope of which represents a true carapace, the author points out 
that “a perfecting of this structure may be demonstrated from 
A. tentaculata through A. actinophora to Cochliopodium. It might be 
conceived that by a further increased tenacity of the cortical zone we 
shall finally be led to those forms of monothalamous Rhizopods whose 
envelope forms only a soft membrane closely embracing the sarcode, 
and which is still so completely at one with the protoplasmic body as 
to accompany it in all its movements and to be constricted simul- 
taneously in the division. 

‘“‘Glancing back once more upon the phenomena which confront 
us in the Amcebiform Rhizopods surrounded by a distinct cortical 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 213 


zone, we shall find in them a welcome elucidation of conditions such 
as have only been guessed at in the case of other Amebe. 

“In the sarcode body more and less fluid constituents are 
present; the former we find at the spots which betray a centrifugal 
movement whether in the pseudopodia or in the advancing part of the 
flowing Ameebe (A. quadrilineata, villosa, tentaculata, &e.). The 
heavier constituents remain behind and are dragged along, and we 
see them finally break into many cushion-like processes of hyaline 
protoplasm. 

“'The pushing forward of the more fluid constituents is effected 
by the action of pressure upon the opposite side ; this is produced by 
the outermost layer of protoplasm at this part acquiring a tougher 
consistency by extraction of water. The latter is widened during the 
flow of the Amewba at the posterior end by all sorts of processes, 
_ lobes, hairs, &¢., which often give the Ameba a peculiar aspect and 
have led to the establishment of distinct species. The sarcode here 
becomes so tough that as the Amba hastens forward it is drawn into 
threads, if the expression may be allowed. 

“If the direction of movement is reversed the previous posterior 
extremity begins to flow, and the most tenacious protoplasm occurs 
on the opposite side. These conditions may be equally well studied 
on the lobate pseudopodia, as also during the retraction of the 
pseudopodium on the surface of which all sorts of humps and folds 
are produced. 

“A tougher cortical zone of this kind is actually to be seen in 
the forms here under consideration. When there is a centripetal 
pressure acting uniformly it surrounds the whole Ameba like a 
‘membrane; if the pressure ceases on all sides the Ameba flattens into 
a disk, the cortical zone liquefies and flows into a clear border of 
more fluid sarcode, but if the pressure acts on one side the liquefaction 
takes place only on the opposite side, and the mode of movement 
which may be called the flow of the Ameba is produced. 

“Tn the formation of individual pseudopodia (see A. tentaculata) 
it is only a few spots that are subjected to these conditions, and in 
accordance with this the tougher cortex dissolves only at certain points, 
making way for the issuing softer sarcode.” 


Protozoa of the White Sea.*— C. Gobi gives a sketch of Professor 
Cienkowski’s report on his expedition to the White Sea, which appears 
in the ‘Proceedings of the Natural History Society of St. Petersburg’ 
in the Russian tongue, and is illustrated with three coloured plates. 

The sea was by no means rich in microscopical organisms, but 
still a few new and interesting forms were found, and are described 
and figured, such as Wagneria mereschkowshkii, 2 new genus and 
species of Protista, somewhat between Haeckelina and Clathrulina ; 
several new Flagellata, Multicilia marina nov. gen. et sp., having a 
protoplasmic body of protean form without nucleus or contractile 
vesicle, but having several cilia; Haxuviaella marina, also new, with 
an ovum-like body, flattened horizontally at the top, with two cilia 
and one or two round marks (Schildchen); Daphnidiwm boreale nov. 

* Cf. ‘Nature, xxv. (1882) p. 328. 


214 SUMMARY OF CURRENT RESEARCHES RELATING TO 


gen. et sp., with a spherical body, prolonged into a curved beak, 
giving origin to one long cilium. In the dead cells of Pylaicella and 
other Pheosporous Alge there was found a colourless form of a 
Labyrinthula which had previously been found thriving in the cells 
of a Lemna. Finally, a new Moner, Gobiella borealis, which shows a 
great resemblance to Vampyrella, but the green contents seem never 
to extend into the pseudopodia. 


BOTANY. 


A. GENERAL, including Embryology and Histology of the 
Phanerogamia. 


Free Cell-formation in the Embryo-sac of Angiosperms.*—Dr. 
F. Soltwedel thus sums up the results of a series of observations on 
this subject on various plants :— 

The mode in which the mature nucleus is developed from the 
homogeneous lump of nuclear substance may be regarded as a forma- 
tion of vacuoles within it. The contents of the vacuoles constitute 
the nuclear sap, the nucleoli and the nuclear network and external 
layer proceeding from the substance of the nucleus. Since in many 
mature nuclei no external substance is to be recognized, and the 
nuclear sap is in these cases always sharply differentiated from the 
surrounding protoplasm, it may be assumed that the nucleus is sur- 
rounded by a nuclear membrane, which may be formed by a chemical 
action either of the nuclear substance or sap upon the surrounding 
protoplasm. 

When the nucleus multiplies, the nuclear substance alone divides, 
and forms first of all the primary spindle. At this stage the nuclear 
sap penetrates into the surrounding protoplasm, the nuclear membrane 
being always absorbed or ruptured. The protoplasm, which now 
advances to the rods of the primary spindle, surrounds them with a 
denser layer, and forms in this way the spindle-fibres. These are 
visible at the poles when the nuclear substance is pressed to the 
equator. After the halves of the nuclear plates separate, the spindle- 
fibres remain between them as empty sacs. 

Coalescence of the nuclei is effected by the disappearance of the 
nuclear membranes at the point of contact of the nuclei, and the union 
of the corresponding constituents. Before the nuclei break up they 
attain a very considerable size; their membranes are finally absorbed, 
the nuclear sap mingles with the surrounding protoplasm, and the 
nuclear substance breaks up, with the formation of vacuoles in the 
interior, into small pieces, which afterwards deliquesce in the proto- 
plasm. The nuclear membranes are made up of small granules, the 
composition of which could not be detected. 


Structure and Division of the Vegetable Cell.j—In a paper on 
this subject Mr. J. M. Macfarlane, Demonstrator of Botany in the 
University of Edinburgh, says that on examining the epidermal 


* Jenaische Zeitschr. f. Naturwiss., xv. (1881) pp. 341-80 (3 pls.). 
+ Trans. Bot. Soc. Edinb. xiv. (1881) pp. 192-219 (2 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 215 


cells of Ornithogalum pyramidale he found what seemed a well-marked 
body inside the nucleolus of a cell, and the same was found on care- 
fully examining the others. The epidermis was quite fresh, and had 
been stained in alcoholic solution of eosin—an excellent stain for 
demonstrating minute structure. Numerous other flowering plants 
were examined, and in the whole of these the new structure was found 
to be present in the cells of the epidermis, lamina, petiole, stem, and 
root, as also in Cryptogams, such as Hquisetum limosum, Chara, Spi- 
rogyra, &c. It is round or slightly oval in outline, and exhibits a 
cleur bounding wall, differentiating it from the substance of the 
nucleolus. Aqueous solution of logwood reveals the outline well, still 
better is a solution of iodine; but preferable to either of these is a 
4 per cent. solution of eosin in common methylated spirit.* 

To this new factor in the vegetable cell the author proposes to 
apply the term nucleolo-nucieus. His investigations led him strongly 
to the conclusion that the nucleolus is also an invariable element ; in 
fact, all the tissue systems of every plant which have come under his 
notice in the present connection have been found to be provided 
invariably with a nucleus, nucleolus, and nucleolo-nucleus, if the cell 
is still active. To ascertain, if possible, the function of these, and 
their réle in division of the cell, he examined Ornithogalum pyrami- 
dale, Scilla bifolia, Spirogyra nitida, and Equisetum limosum, and the 
general results as to division are summed up thus :— 

(a) In division of the cell the nucleolo-nucleus probably divides 

first. 

(6) The nucleolus undoubtedly divides next, and this is followed 

by division of the nucleus. 

(c) During division of the nucleus a nuclear plate with nuclear 

disk is formed occasionally. 

(d) If a septum is laid down, this is always preceded by formation 

of a nuclear barrel and cell-plate. 


Fertilization of Apocynacer.{—F. Ludwig gives a comparative 
sketch of the various very interesting modes of cross-fertilization in 
the Apocynacesx, especially in the genera Apocynum, Vinca, and 
Nerium, uUlustrated with woodcuts. 


Cross-fertilization and Distribution of Seeds.—F. Hildebrand 
describes the peculiar arrangements for cross-fertilization in Hremurus 
spectabilis (Liliacez), in which the perianth withers before either the 
male or female organ is mature; and in Rhodora canadensis, in which 
self-fertilization is almost absolutely prevented by the position of the 
stigma. 

on Aponogeton distachyum the distribution of the seeds is promoted 
by their possessing air-containing intercellular spaces, by means 


* The author also says that he examined a preparation of cerebellum. “In 
the large multipolar nerve-cells a nucleolus has long been known to exist, but 
inside many nucleoli this new structure was quite visible. .... It has been 
mentioned before casually, but no importance was attached to it. On looking 
over various zoological works one finds that it is figured repeatedly.” 

+ Bot. Centralbl., viii. (1881) pp. 183-9. 

} ‘ Flora,’ Ixiv. (1881) pp. 497-504 (1 pl.). 


216 SUMMARY OF CURRENT RESEARCHES RELATING TO 


of which they float on the water—-an arrangement similar to that 
found in the white and yellow water-lilies. 


Swelling of the Pea.*—F’. Schindler has investigated the phe- 
nomena of the swelling of the seeds of Papilionacez in the case of ten 
varieties of Pisum sativum. He finds all the three stages indicated by 
Nobbe well displayed in all cases ; but each variety was characterized 
by special peculiarities. The power of swelling was found in general 
to be in proportion to the specific gravity of the seed. The following 
may be stated as the general results of the investigation :— 

The first penetration of water into the testa of the pea usually 
takes place through the micropyle, which, with few exceptions, 
provides an open communication with the external air. Advantage is 
next taken of the longitudinal fissure of the hilum. The anatomical 
structure of the layer of’ stellate parenchyma presents great facilities 
for swelling ; and this absorbs a large proportion of the water admitted 
through the micropyle, the quantity being sufficient for the first 
development of the embryo. The spiral vessels of. the testa serve as 
capillary tubes for the conduction of water. 


Aril of Ravenala.j—According to Dr. F. R. v. Hohnel, the aril 
of the seeds of the “ traveller’s tree,’ Ravenala madagascariensis, is, 
when fresh, of a beautiful azure-blue colour, and is the only known 
example of an aril from which an oil is obtained for economical 
purposes.{ The author believes that in this instance the bright colour 
prevents the seed being eaten by birds. The aril is entirely cellular 
in its structure, the cells being elongated, thin-walled, and with very 
small intercellular spaces. They are filled with a homogeneous, 
finely granular, blue mass, consisting of protoplasm and an oil which 
contains the blue pigment in solution. This substance appears to be 
peculiar to the species, and of unknown composition. 


Structure and Mechanics of Stomata.$— S. Schwendener describes 
in detail the points of anatomical structure connected with the 
opening and closing of stomata. 

Of the contrivances on which the motility of the guard-cells 
depends, the most important is that which the author describes as the 
“epidermal hinge” (Hautgelenk), which is placed right and left of 
the guard-cells in the outer wall of the adjoining epidermal cells, It 
consists of a thin spot in this wall, never wanting in plants with a 
thick-walled epidermis, though frequently absent from those where it 
would be superfluous, viz. where the outer wall of the epidermis is 
thin. In those cases where the stomata are depressed, they are sur- 
rounded by delicate lamelle of cellulose, which constitute the hinge, 
attached either to the margins of the fissure, or to the round opening 
which perforates the outer wall of the epidermis. 

The wall which separates the guard-cell from the adjoining 


* Wollny’s Forsch. aus Geb. der Agriculturphysik, iv. (1881) p. 190. See 
Bot. Centralbl., vii. (1881) p. 360. 

+ Oesterr. Bot. Zeitschy., xxxi. (1881) pp. 386-7. 

t The aril of the nutmeg (mace) yields a well-known oil.—Ep. 

§ MB. K. Akad. Wiss. Berlin, 1881, pp. 8837-67 (1 pl.). 


a 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. Din 


epidermal cell, if not thin and easily permeable, as is the case where 
the guard-cells are weak in mechanical structure, has invariably a thin 
spot which is readily permeable. Where the wall of the guard-cell is 
otherwise entirely cuticularized, this spot consists of ordinary cellu- 
lose. The opposite ventral wall of the guard-cell, bounding the 
fissure itself, also has always a thin spot. When the cuticle covers 
the ventral wall of the guard-cells up to the fissure, it is not inter- 
rupted at the thin spot. These thin strips constitute a hinge. 

Elsewhere the walls of the guard-cells are thickened in a great 
variety of ways; the outer and inner parts of the ventral surface 
usually prismatically. By these prismatic thickenings, when the 
guard-cells become more turgid, a strong elongation of the thin-walled 
dorsal side is brought about, by which the guard-cells are made to 
curve, because the thickenings of the ventral wall give them increased 
power to withstand traction. No curvature of the guard-cells can 
take place here in consequence of any greater increase in length of the 
dorsal wall. The motility of such guard-cells appears therefore to 
be less when mature than when young, when the form of the cells 
more nearly resembles those with prismatic thickenings. In many 
plants it is only the thickening ridges which face the interior of the 
leaf that are capable of curving. The thickenings gradually dis- 
appear at their ends, and do not usually coalesce. The guard-cells 
are often considerably higher at the two ends than at the middle. In 
many thick phyllodes and evergreen leaves the very narrow cell-walls 
are bounded above and below by strong thickening stripes, often fur- 
nished with prominent cuticular ridges. 

Those stomata of which the guard-cells have no cell-cavities are 
often comparatively immotile, in extreme cases, perhaps, absolutely so. 

The mode of motion may be made out by comparing the open and 
closed conditions of the stomata. For this purpose both vertical and 
transverse sections should be made; and care must be taken to allow 
for the increase of turgidity caused by glycerin. ‘The general 
results of a careful series of measurements is that the size of the 
guard-cells is greater when the fissure is open than when it is closed. 

The movements are caused by increase and decrease of the hydro- 
static pressure in the guard-cells. When the turgidity is increasing, 
the increase of the thin dorsal wall of the guard-cell amounts to about 
9 per cent., and the increase in volume of the entire guard-cell to 
about 17 per cent. The hydrostatic pressure necessary to produce 
this effect on a cell-wall 1 or 2» thick, “s respectively that of 
5 or 10 atmospheres. It is only when the pressure in the guard- 
cells exceeds that of the adjoining epidermal cells that the stoma can 
open. This is effected by a curvature of the guard-cells, caused by 
the difference in structure of the dorsal and ventral walls, as can be 
shown experimentally by a caoutchouc-tube. 

When there is no tension the stomata are open only in some water 
plants. In some Monocotyledons (as Tradescantia discolor) there is 
a difference from the normal structure as regards the changes in form, 
the peculiar structure causing an expansion of the guard-cells in a 
direction vertical to the surface of the leaf, which increases and 


218 SUMMARY OF CURRENT RESEARCHES RELATING TO 


decreases with the degree of turgidity. When there is no tension 
the ventral wall projects; and the thin spot then acts as the hinge 
between the thickenings. 

The result of the movement is (in Helleborus) that the anterior 
chamber of the stoma remains unchanged, while the posterior chamber 
is greatly narrowed by the closing; the ventral walls of the guard- 
cells turning on their outer lines of attachment, and bending con- 
siderably. The mechanical nature of this process may be determined 
by observing the change in form of the cell-cavity. When there is no 
tension, the transverse section of the cavity represents a scalene 
triangle, pressure tending to change it to an equilateral form, which 
causes the movement. That this must be the case the author has 
proved by an experimental apparatus constructed for the purpose. 

As regards the purpose of each separate part of the stoma, the 
two thickening-ridges may be compared to a half-open portfolio; the 
delicate lamella of cell-wall which unites them to the hinge or back. 
The uniform strength of the thickening-ridges from one end to the 
other of the fissure is a contrivance to assist the curvature. When 
the posterior chamber of the stoma is enlarged by the increased 
turgidity of the guard-cells, the breadth of the hinge increases, as is 
essential. Turgidity then causes, firstly, a curvature of the cells, and 
in the second place an enlargement of the posterior chamber. With 
increase of age the thickenings become stronger, the opening of the 
stoma being thus rendered more difficult, and, finally, impossible. In 
many cases they are ultimately closed by thyllose structures. 

The turgidity of the guard-cells is dependent on the influence of 
light. The fissure was always open (in Amaryllis formosissima) after 
the plant had been exposed for from one to two hours to direct sun- 
light; while the stomata were always closed when the plant had 
remained for some time in the dark. Within ordinary variations of 
temperature heat alone does not cause the fissure to open. 


Callus-plates of Sieve-tubes.*—E. Russow has successfully em- 
ployed aniline blue for colouring the callus-plates of sieve-tubes. An 
aqueous solution of this pigment is taken up in larger quantities and 
more firmly held by these plates than by the other parts of the sieve- 
tubes, out of which it can be washed by water. The same effect was 
not produced by other aniline dyes, as aniline brown. The fine 
structure was best exhibited by treating it with chloriodide of zinc con- 
taining an excess of potassium iodide either before or after colouring 
with the aniline blue. 

Out of a large number of species examined, Russow found callus- 
plates in Alsophila australis, Balantium antarcticum, Osmunda regalis, 
Equisetum arvense (but not in Pteris aquilina, Marsilea, or Lycopo- 
dium); and in all families of Gymnosperms, Monocotyledons, and 
Dicotyledons. 

In Abies Pichta large callus-cushions were found, composed of 
radially arranged parts with a crystalline appearance, which were 
evidently doubly refractive. The callus-layers of the sieve-plates of 


oe Dorpater Naturf.-Ges., 1881, April 23. See Bot. Ztg., xxxix. (1881) 
p. 725. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 219 


Abies excelsa and Larix sibirica were partially dissolved by water or 
glycerin, the parts of the cortex containing them being taken from 
the stem in April. The sieve-plates of Hquisetum are perforated by 
“ combining-bundles,” which have not been found in true ferns. 

The author states that the callus-layers are usually to be found 
only in the younger or even the youngest parts of the cortex while still 
in a state of vital activity, and considers it probable that the specific 
function of sieve-tubes commences with the formation of callus, and 
lasts only so long as this structure endures. 


Phyllomic Nectar Glands in Poplars.*—W. Trelease calls atten- 
tion to the fact that these glands have been very generally overlooked, 
and that they have been considered of little value by the systematic 
botanist. He accounts for this by their being occasionally suppressed, 
and by their limitation to the earlier-formed leaves. Still, most of 
the American botanists refer to them, and Michaux figures them in 
his monograph of the genus. In May 1880, Mr. Trelease’s attention 
was drawn by the action of some bees to examine the leaves of a 
small aspen. The tree was covered with its newly expanded foliage, 
and the bees were flying from leaf to leaf; they were seen to be 
collecting nectar, which was poured out from a double gland at the 
base of each leaf. These glands were placed on the upper surface 
of the petiole at its union with the blade. On section and micro- 
scopical examination, they showed the usual structure. They were 
found not to occur on all leaves, but as a rule only on the first haif- 
dozen or less which appear on each branch in the early spring; and 
later on in the season, when these have fallen off, one may sometimes 
examine all the leaves without detecting a single glanduliferous one, 
and this on a species which produced them in abundance earlier in 
the year. From an examination of the American species it would 
seem that the greater number possess two or more distinct or con- 
fluent glands, situated where the blade and petiole join; and in those 
few species where none were discovered it is quite possible that a 
closer examination in the spring-time may show that they exist. 
Thus on P. tremula, the weeping variety, a careful examination in 
early May failed to show a single gland; but a week or two later, 
after several days’ rain, the young branches grew very rapidly for 
a short time, unfolding many new leaves, and the first three or four 
of these on each branch bore large and active glands. The nectar is 
greedily gathered by insects, chiefly Hymenoptera and Diptera. The 
most numerous were the ants, who, as is usual in such cases, would 
fight rather than give up a good position near a nectar-secreting 
gland. The author regards these glands as protective. 


Histology of Urticacee.t— Karl von Demeter publishes (in 
Magyar), an exhaustive account of the histology of Urticacezx, espe- 
cially in relation to Boehmeria biloba, though reference is made also 
to many other species. 


* Bot. Gazette, 1881. Cf. ‘ Nature,’ xxv. (1882) pp. 327-8. 
+ K. von Demeter: ‘ Histology of Urticacez, with special reference to Boch- 
meria biloba’ (in Magyar), Klausenburg, 1881, 43 pp., 2 pls. 


220 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Structure of Podostemonacee.*—Prof. E. Warming has carefully 
studied the anatomy and morphology of this order of flowering plants: 
especially in the cases of Podostemon Ceratophyllum and Mniopsis 
Weddelliana and Glazioviana. The following are his chief points :— 

Stomata are altogether wanting. The epidermal cells are more or 
less polygonal; the cuticle is weak. The fundamental tissue consists 
mainly of parenchymatous cells, usually somewhat elongated longi- 
tudinally, especially the nearer they are to the fibrovascular bundles. 
Their walls are often somewhat collenchymatous, swelling easily in 
caustic alkali, by which a central lamella is distinctly visible. Inter- 
cellular spaces are either entirely wanting or extremely inconsiderable. 
All the cell-walls consist of pure cellulose, with the exception of the 
tracheides of the xylem which are slightly lignified. Large quantities 
of starch are often present in the fundamental tissue. The cell-walls 
have a strong tendency to excrete silica, which frequently entirely 
fills up the cell-cavities. This takes place in all the organs, but 
especially in the epidermis. 

The roots are plagiotropous and distinctly dorsiventral, and are 
hence often flat; they contain sieve-tubes, and nearly always have 
a root-cap, which is often oblique. They have a great power of 
regeneration when detached. They attach themselves by means of 
root-hairs, and of peculiar organs which he terms haptera, consisting 
of protuberances which spring from the under side of the roots. 

Each fibrovascular bundle may be traced up into a leaf; every leaf 
receiving one bundle. They consist, in the stem, of soft bast (sieve- 
tubes and cambiform) with a few spiral and annular vessels, and 
are supported by a collenchyma which is especially developed on the 
dorsal side; its cells have a strong resemblance to true bast-cells. 
The epidermis of the leaves is not strongly developed ; it contains 
chlorophyll, and some of its cells are prolonged into short hairs. The 
mesophyll resembles the fundamental tissue of the stem; there is no 
palisade-tissue. The vascular bundles of the veins are but feebly 
developed ; sieve-tubes were not observed; but, on the other hand, 
sheaths, composed of true bast-fibres. 


Pitchers of Cephalotus follicularis.t—In continuation of his 
_ previous researches on the morphology of the pitchers of pitcher- 
bearing plants, A. W. Eichler traces the development of those of 
Cephalotus follicularis and Nepenthes phyllamphora. In the former plant 
the pitcher is certainly the modified lamina; in the latter possibly, 
as Hooker believes, an appendicular formation ; in a certain sense an 
excessively developed gland, separated by means of a stalk from the 
flat basal part which represents the true lamina. Certainly the lid 
of the pitcher of Nepenthes is not the true blade, as many suppose. 


Action of Light on Vegetation.t—Professor N. Pringsheim thus 
sums up the results derived from his previously recorded observations. 


* Vidensk. Selsk. Skr. Rakke, VI. ii. (1881) 6 pl. (French abstract). See 
Bot. Centralbl., viii. (1881) p. 108. 

+ JB. K. Bot. Gart. Berlin, i. (1881) pp. 193-7. 

t MB. K. Akad. Wiss. Berlin, 1881, pp. 504-35, 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 22K 


The primary action of the rays of the sun on vegetation consists 
in thermic and photo-chemical effects, the influence of which on the 
separate constituents of the cells is directly recognizable in intense 
light. The photo-chemical effects relate exclusively to the behaviour 
of the plant towards the oxygen and carbonic acid of the atmosphere ; 
they are simply changes of intensity in the interchange of gases. 
These have been fully determined in the absorption of oxygen, less 
completely in that of carbonic acid. It cannot be then that light 
produces any other effect on the plant than the thermic and the 
photo-chemical. 

All the action of light on the phenomena of vegetable life, not 
merely on growth and metastasis, but also the so-called mechanical 
and vital movements of irritation caused by light, can readily be 
traced to purely thermic and photo-chemical effects. A more exact 
knowledge of them requires, however, a special investigation of the 
behaviour of those constituents of the cell which are sensitive to light, 
i.e. which are photo-chemically excitable. For an investigation of 
them, and of their differences from those constituents which are not 
excitable photo-chemically, the reader is referred to the author’s 
treatises on the functions of chlorophyll and the action of light 
upon it.* 

Production of Heat by Intramolecular Respiration.t—Dr. J. 
Hriksson has made a series of observations for the purpose of deter- 
mining the amount of heat, and the length of time for which it lasts, 
caused by the intramolecular respiration of plants. The experiments 
were made with the inflorescence of Aroidez, the flowers of other 
plants, ripe fruits, germinating seeds, and yeast-cells, care being taken 
to exclude the access of atmospheric oxygen. In most cases the eleva- 
tion of temperature under these circumstances did not exceed 0-2° C., 
while access of air caused a rise of about 1°. With seedlings of lentil 
the elevation of temperature continued for six days; with buckwheat 
for two days. In the case of fermenting yeast, however, an elevation 
of 3°9° was observed, which was not increased by the subsequent 
letting in of a stream of air. Yeast not in a state of fermentation 
showed only the slight rise of temperature common to other plants. 


Physiological Functions of Transpiration.{—F. Reinitzer pro- 
pounds the theory that transpiration is an injurious agent, a necessary 
evil, in the life of the plant. This view he founds on the fact that 
transpiration exercises a retarding influence on growth. He regards 
woody tissue as the cause of rapid movements of water in the plant, 
rather than as being—according to Sachs’s view—formed as the result 
of such movements. 


Metastasis.§— The first volume of Pfeffer’s ‘Handbook of 
Metastasis and Metacrasis’ (Stoffwechsel u. Kraftwechsel) is occupied 


* See this Journal, iii. (1880) pp. 117, 480; i. (1881) p. 479. 

+ Unters. aus dem bot. Inst. Tubingen, i. (1881). See Bot. Ztg., xxxix. 
(1881) p. 597. 

{ SB. Akad. Wiss. Wien, Ixxxiil. (1881) pp. 11-36. 

§ W. Pfeffer, ‘Stoffwechsel,’ 383 pp. (39 figs.). Leipzig,1881. 


929, SUMMARY OF CURRENT RESEARCHES RELATING TO 


with the former of these subjects, and is divided under the following 
heads :— 

The physical properties and molecular structure of organized 
bodies ; including the form of the micella, the mechanical phenomena 
of swelling, the change of physical properties occasioned by it, and 
the structure of protoplasm. ‘The mechanical phenomena of meta- 
stasis, including the osmotic properties of cells, cuticle, and cork, the 
osmotic pressure in cells, the power of selection, the specific osmotic 
capacity of the various organs, and the properties and influence of the 
soil. The mechanical phenomena of the interchange of gases, in- 
cluding the passage of gases through the cells and cell-walls, stomata 
and lenticels as conductors of gases,the pressure of gases, &e. The 
movements of water, including transpiration and the excretion of 
water. Food-materials, including the production of organic substances 
and decomposition of carbonic acid gas, the absorption of organic 
food, the synthesis of nitrogenous substance, and the composition of 
the ash. The movements of fluid and solid substances, as gums, 
resins, pigments, and other nitrogenous and non-nitrogenous sub- 
stances, the constituents of the ash, &c., and the movements which 
take place during germination. Respiration and fermentation, in- 
cluding the products of respiration, the relation between normal and 
intramolecular respiration, and the influence of external conditions. - 


Phosphorescence in Plants.*—L. Crié calls attention to some 
new cases of phosphorescence in plants. As is known, the flowers of 
Phanerogams will, under certain circumstances, show phosphorescent 
gleams, and a few years ago, in stormy weather, the author saw 
phosphorescence produced by the flowers of Tropewolum majus. This 
emission of light is characteristic of Fungi, especially Agaricus olearius, 
A. igneus, A. noctilucens, A. Gardneri, A. lampas, and several other 
Australian forms, also Awricularia phosphorea and Polyporus citrinus. 
The luminous strings of Rhizomorpha subterranea are readily obser- 
vable in the Pontpéan mine, near Rennes. M. Crié also cites Rhizo- 
morpha setiformis and a particular form of Rhizomorpha which he has 
observed in the interior of branches of the elder. Having divided a 
number of these branches in the interior of which filaments of a 
ERhizomorpha were developed, between the wood and the pith, the 
author was surprised to see very faint gleams produced by the fungus. 
It possesses a reproductive apparatus which seems by its organization 
identical with the conidiophorous clavicle of Stilbum. Only those 
filaments that bore abundance of conidia produced phosphorescent 
gleams. Finally, Xylaria polymorpha, gathered on old stumps in a 
garden, emitted faint white gleams comparable to those produced by 
phosphorus when oxydizing. In both cases the author considers 
the phosphorescence to be an effect of the respiration of the conidio- 
phorous portions of Rhizomorpha and Xylaria. 


Transformation of Starch.t—W. Detmer states that the presence 
of carbonic acid greatly promotes the transformation of starch into 


* Comptes Rendus, xciii. (1881) pp. 853-4. 
+ SB. Jenaisch. Ges. fiir Med. u. Naturw., 1851, June 17. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 223 


diastase in the vegetable cell; and the same effect is produced by 
small quantities of organic acids as citric acid. The degree of acidity 
of any particular part of a plant is constantly changing. He believes 
also that the chief cause of the turgidity of the cell is the presence of 
vegetable acids, which have the special quality of inducing endosmose, 
and the presence of which greatly promotes the growth of the plant. 


Occurrence of Allantoin in the Vegetable Organism .*-—If 
branches of woody plants covered with buds are cut off and placed in 
water until the buds unfold, the young shoots and leaves are found to 
be rich in asparagin, formed most probably by decomposition of albu- 
minoids. EH. Schultze and J. Barbieri have undertaken a number of 
experiments for the purpose of determining whether in these cases, in 
addition to the amide, other nitrogenous substances are found. By a 
similar treatment they obtained, besides asparagin, a highly nitro- 
genous body, which appears to be identical with allantoin both in its 
- composition and in its reactions. This derivative of uric acid was 
found in no inconsiderable quantity, amounting to from 0°5 to 1-0 
per cent. of the air-dried substance. 


Excretion of Water on the Surface of Nectaries.;— Dr. W. P. 
Wilson attributes this phenomenon to osmose, and not to any internal 
pressure; a view which he supports by the fact that washing the 
nectaries with water and then drying them with blotting-paper stops 
the excretion. With regard to the influence of light on the excretion, 
with some plants no effect was observed, while with others it was 
greatly increased by direct sunlight. © 


Determination of the Activity of Assimilation by the Bubbles 
given off under water.t—Sachs proposed the method of determining 
the intensity of the assimilation of water-plants by counting the number 
of bubbles of gas given off in a certain time. To this plan the objec- 
tion was made that the bubbles might be the result of some other cause 
than assimilation. Dr. F. Schwarz has now confirmed the accuracy 
of Sachs’s method, by determining that the presence of carbonic acid 
in the surrounding water is an indispensable condition to the giving 
off of the strings of bubbles. 


Detmer’s Vegetable Physiology.s—The 7th section of Schenk’s 
‘Handbook of Botany’ is occupied by a treatise on Physiology by 
Detmer. The following are the subjects comprised in it :—Food- 
materials of Plants, including the Process of Assimilation ; Origin of 
the Proteimaceous Substances; Composition of the Ash of Plants; 
Organic Compounds as Food-materials; the Molecular Forces in 
Plants; the Movements of Gases; the Absorption of Water; the 
Movements of Fluids ; the Absorption of Mineral Substances; and 
the Process of Metastasis. 


* Berichte der deutsch. chemisch. Gesellsch. xiv. p. 1602. See ‘Natur- 
forscher,’ xiv. (1881) p. 481. 

+ Unters. aus dem bot. Inst. Tiibingen, i. (1881). See Bot. Ztg., xxxix. 
(1881) p. 545. 

¢{ Unters. aus dem bot. Inst. Tiibingen, i. (1881). 

§ W. Detmer, System d. Pflanzenphysiologie, 1881. 


224 SUMMARY OF CURRENT RESEARCHES RELATING TO 


B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 


Development of Sporangia.*—K. Goebel continues his researches 
into the comparative history of development of the sporangia of the 
higher cryptogams.t These are all characterized by the presence of 
an “archespore.” 

The Marattiaceze were examined chiefly in the example of Angio- 
pteris evecta. The sporangia are developed from a group of superficial 
cells, on the receptacle formed by the superficial cells of the depression 
of the sorus, corresponding to the placenta of phanerogams. Here 
also it is the hypodermal terminal cell of the axial row of cells of 
the rudiment of the sporangium that gives rise to the whole of the 
sporogenous tissue. By the formation of anticlinal and periclinal 
walls in the cell above the archespore, it becomes subsequently im- 
bedded in the interior of the tissue. The Tapetenzellen arise from 
the cells which bound the archespore. Marattia cicutefolia and alata 
agree in all essential points. 

In Ophioglossum it is probable that the sporogenous tissue also 
proceeds from either a hypodermal or a superficial cell. Cells are 
produced by periclinal divisions of the parietal cells, which very 
soon become compressed, and which may also by analogy be termed 
Tapetenzellen. The processes are very similar in Botrychiwm and 
Anemia. 

The investigations on Equisetum do not confirm Milde’s view that 
the sporangia are produced on the surface of leaves. The apical cell 
of the sporangial fructification becomes, on the contrary, soon enclosed 
in a small-celled tissue. 

The author enters with considerable detail into the development 
of the sporangia of the Psilotez, especially Psilotum and Tmesipteris. 
He agrees on the whole with the view of Sachs and Strasburger that 
the sporangia are here not the product of the leaves, but are more or 
less imbedded in the tissue of short lateral axes. The Psilotee are, 
therefore, widely separated from the Lycopodiacee by this difference 
in structure. 

In Selaginelia the sporangia arise from superficial cells of the 
vegetative apex of the stem, which he immediately above those from 
which the apex of the leaf proceeds. The archespore is again the 
hypodermal terminal cell of the axial row. The radially elongated 
cells which clothe the inner surface of mature sporangia may be 
regarded as Tapetenzellen. ‘‘he outermost of them are given off by 
the archespore ; while those near the pedicel are separated from the 
adjacent cells. 

The morphological value of the sporangia of the Archegoniatz, 
therefore, varies greatly. 

The author then compares the development of the sporangia of the 
higher cryptogams with that of the pollen-sacs or microsporangia of 


* Bot. Ztg., xxxix. (1881) pp. 681-94 ; 697-706; 713-20 (1 pl.). 
+ See this Journal, iii. (1880) p. 987. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 225 


conifers, and finds a very close correspondence between them. The 
prolongation of the staminal shield which, in most Cupressinex, pro- 
tects the pollen-sacs when young, he regards, from analogy with ferns, 
~ as an indusium. 

To the view previously expressed that the divisions in the embryo- 
sac of phanerogams are nothing but divisions of the archespore, he 
adds two illustrative examples, in Callitris quadrivalvis and Cupressus 
sempervirens, in which the reduction in the divisions of the embryo- 
sac does not go so far as usual. 

The author concludes with the following classification of vascular 
cryptogams and phanerogams. 

I. Leptosporangiate. 

A. Filices. 

(1) Homospore (Polypodiaceze, Gleicheniaceze, Cyathe- 
aces, We. ). 
(2) Heterospore (Salviniacez). 

B. Marsiliacez (Marsilia, Pilularia). 

II. Eusporangiate. 

A. Filicales. 

(1) Marattiacez. 

(2) Ophioglossacesze. 
B. Equisetinex. 

(1) Calamites. 

(2) Equisetacez. 

C. Sphenophyllaceze (the formation of the sporangia re- 
sembles that of the heterosporous Lycopodinex, that 
of the leaves corresponds to Equisetum). 

D. Lycopodinez. 

(1) Lycopodiacez. 
a. Homospore (Lycopodium). 
b. Heterospore (Lepidodendron, Sigillaries ?). 
(2) Psilotacez. 
3) Selaginellacez. 
2} Isoetez. 
EK. Gymnosperme. 
I’, Angiosperme. 


Lenticels of the Marattiacee.*—H. Potonié has examined the 
structure of the lenticels in the leaf-stalk of Angiopteris crassipes, 
evecta, Teysmanniana and Willinkit, and Marattia fraxinea; and 
describes those of A. evecta in detail. In all the Marattiacew the 
stomata are arranged in rows, in the centre of which lenticels are very 
commonly found. Their production begins by the walls of one or 
more stomata, and of the epidermal cells which surround them, 
becoming brown and dry; the subjacent parenchyma then developing 
into phellogen by repeated periclinal divisions, and the outermost of the 
cell-layers also becoming brown and dry. The cell-walls cuticularize, 
and small interstices appear between the dry cells; the space occupied 


* JB. K, Bot. Gart. Berlin, i. (1881) pp. 307-10. See Bot. Centralbl., viii, 
(1881) p. 70. 
Ser. 2.—Vot. II. Q 


226 SUMMARY OF CURRENT RESEARCHES RELATING TO 


by the entire tissue decreases, and the lenticels appear somewhat 
depressed. This firm dry mass of tissue constitutes, therefore, a pro- 
tection to that which lies beneath, and its physiological function is 
the same as that of the lenticels in flowering plants. 


Stomata in the Leaf-stalk of Filicinee.*—H. Potonié states that 
the arrangement of the stomata in the leaf-stalk of Filicinex has a 
direct relation to the anatomical structure of the stem and to the 
development of the mechanical tissue. The latter is always peripheral, 
and forms the cylinder of stereome or sclerenchyma; but it may 
either be hypodermal, or separated from the epidermis by a paren- 
chymatous assimilating tissue. In the former case the stomata are 
arranged in two rows on the two sides of the leaf-stalk; in the latter 
case they are distributed over its surface. The former arrangement 
occurs in Adiantum, Anemia, Cyathea, Cystopteris, Davallia, Dicksonia, 
Gymnogramme, Lomaria, Lygodium, Nephrodium, Nephrolepis, Onoclea, 
Pellea, Polypodium, and Pieris; also in Hymenophyllum and Tricho- 
manes, as far as relates to the structure of the stem. The second form 
occurs in Alsophila, Asplenium, Marattiacez, Marsilia, and Todea, 
although in the last the parenchyma subsequently passes into stereome. 

The author gives the following classification of Filicinee in 
reference to this point of structure :—1. Without stomata in the leaf- 
stalks: Hymenophyllacee [Salviniacew]. 2. Stomata arranged in 
two rows: Polypodiaces, Cyatheacere, Schizeeacee [Gleicheniace:e]. 
3. Stomata distributed over the surface of the leaf-stalk : Osmundacez, 
Marattiacee, Ophioglossacez, Marsiliacee. 


Adventitious Buds on the Lamina of the Frond of Asplenium 
bulbiferum.}—E. Heinricher has pursued his investigations on this 
subject, especially as regards the youngest stages, for the purpose of 
confirming his previous statement} that these buds may originate 
from a single superficial cell, in which triangularly segmented apical 
cells were formed. The general result obtained may be stated as 
follows :—These adventitious buds proceed from a single superficial 
cell, which proceeds immediately to the formation of a three-sided 
apical cell, This apical cell is usually the result of three divisions ; 
but cases are depicted in which it results from two and from four 
divisions respectively. The conclusion of the author is, therefore, 
at variance with that of A. Zimmermann, that several epidermal cells 
may take part in their formation. 


Anatomy and Classification of Schizeacee.s—K. Prantl pub- 
lishes a preliminary treatise, occupied chiefly with the classification of 
this tribe of ferns. The following are the genera and subgenera 
which he adopts:—(1) Lygodium (Palmata, Flexuosa, Volubilia) ; 
(2) Mohria; (3) Aneimia (Trochopteris, Hemianeimia, Ewaneimia, 
Aneimiorrhiza) ; (4) Schizea. 


* JB. K. Bot. Gart. Berlin, i. (1881) pp. 310-17. - See Bot. Centralbl., viii. 
(1881) p 70. 

+ SB. K. Akad. Wiss. Wien, Iaxxiv. (1881) p. 115-20 (1 pl.). 

¢ See this Journal, ii. (1879) p. 597. 

§ Engler’s Bot. Jahrb., ii. (1881) p. 297. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 227 


Biological peculiarity of Azolla caroliniana.*—M. Westermaier 
and H. Ambronn have observed that this species presents the pecu- 
liarity of throwing off the root-cap from older roots, a great number 
of hairs being also formed at the apex. An organ is thus produced 
which resembles the submerged leaf of Salvinia in both form and 
function. A structure which is neither normal leaf nor normal root 
is formed, in Azolla by the metamorphosis of a true root, in Salvinia 
by the abnormal development of an organ which originates as a 
normal leaf. These root-hairs of Azolla caroliniana are produced in 
moderately regular transverse rows, each proceeding from a segment 
of the triangular-pyramidal apical cell. This tendency reaches at 
length the apical cell and youngest segments, and causes the root-cap 
to be thrown off. 

Muscinee. 


Female Receptacle of the Jungermanniee Geocalycese.f{— 
Leitgeb has established the general rule that the female receptacle of 
the Jungermanniez always originates in the apex of the shoot, and 
that wherever archegonia are found on older parts of the stem, they 
are always products of a lateral shoot. This rule applies to all 
Hepatice ; there is only this point of difference, whether or not the 
apical cell is completely absorbed in the formation of the archegonia. 
In the former case the receptacle then actually occupies the apex of 
the axis, which it does not appear to do in the latter case. These 
two modes of life of the Hepaticee he terms acrogynous and anacro- 
gynous. No exception was found to this rule in a very large number 
of species examined. In all cases the origin of the archegonia at 
spots distant from the apex of the stem can be traced back to an inter- 
calary lateral shoot. To this case belong the archegonia which spring 
from the ventral side of the stem in Calypogeia, Geocalyx, and Sarco- 
gyne. But in the family of Geocalyces there are some genera in 
which the archegonial receptacles have not a ventral insertion, but 
either stand at the apex of a shoot, or the mouth of the fertile tube lies 
on the dorsal side of the stem. 

The most remarkable peculiarities are presented by Gongylanthus 
ericetorum, from Madeira, where all the archegonial receptacles are 
seated in a fork of the stem, forming also the close of an axis, the 
apical cell of which is used up in this formation. In contrast to the 
rest of the European Geocalycex, the archegonial receptacles are in 
this species produced at the apex of normally leafy aerial shoots. 
They are always preceded by the production of lateral branches, the 
rapid and early development of which causes their insertion to 
coalesce completely with the imbedded receptacle, which projects as a 
protuberance on the ventral side. The consequence of this is that the 
receptacle is completely pressed aside from the margin of the fork to 
the dorsal side of the shoot. This displacement must not be regarded 
as a phenomenon which takes place only on the reproductive shoots ; 
it is a necessary result of the earlier development of the lateral shoot, 

* Abhandl. Bot. Ver, Prov. Brandenburg, xxii. (1880) pp. 58-61 (1 pl.). See 
Bot. Ztg., xxxix. (1881) p. 580. 

+ SB. K. Akad. Wiss. Wien, Ixxxiii. (1881). 

Q 2 


228 SUMMARY OF CURRENT RESEARCHES RELATING TO 


and of the hyponasty which belongs also to the apex of the sterile 
shoots, and which does not afterwards disappear, but becomes fixed 
in consequence of the origin of the female receptacle, and of the arrest 
of growth in length. The genus, therefore, presents no difference 
from the rest of the acrogynous Jungermanniez in the position of the 
female receptacle. 

In Podanthe, Lophocolea, and Gymnanthe the receptacle, and hence 
the fertile tube, are terminal. The normal production of lateral shoots 
ceases in these genera before the formation of the female receptacle. 
Lindigina presents as a rule the same peculiarities as Gongylanthus ; 
while Marsupidium more closely resembles in this respect Calypogeia 
and its allies. The reproductive shoots originate in an intercalary 
manner on the ventral side. 


Vegetative Reproduction of Sphagnum.*—C. Warnstorf has 
observed that when tufts of Sphagnum squarrulosum are decapitated by 
mowing, the stems put out young buds in the neighbourhood of the 
tufts of branches, each bud possessing a new cone of growth. These 
buds develope tufts of branches, which for a time derive their nourish- 
ment from the parent stem, but soon acquire the power of carrying on 
existence as separate individuals. This property, together with that 
of indefinite apical growth, give to the turf-mosses an almost unlimited 
power of development and reproduction, if only they are supplied 
with sufficient moisture. 


Fungi. 


Action of Light on Fungi.j}—Professor Karl Regel states that 
Pilobolus crystallinus and Mucor mucedo exhibit positive heliotropism 
in white light, and also in mixed blue and mixed red rays. In one- 
coloured red light Pilobolus also exhibits positive heliotropism. 
Mixed blue rays produce a much greater heliotropic effect on both 
species than mixed red rays. Neither the intensity of the light nor 
the temperature exercises any influence on the kind of heliotropism. 
While sunlight promotes the development of spores and rapid growth, 
darkness arrests both. The strongly refrangible are more favourable 
than the less refrangible rays for both these processes. The hyphe 
grow more rapidly in length in white light than in darkness ; the less 
refrangible rays are more favourable to this process than the more 
refrangible. The formation of sporangia and of spores takes place 
perfectly normally in Pilobolus both in white and in mixed blue and 
red light, and also in darkness; but most rapidly in white light, next 
in blue, next in red, and most slowly in darkness. 


Chemical Nature of the Cell-wall in Fungi.{—It is well known 
that the substance of which the cell-membrane in Fungi is composed 
does not display the ordinary reactions of cellulose ; and it has hence 
been described as a peculiar substance, under the name “ Fungus- 
cellulose.” Karl Richter has determined that this view is incorrect, 


* Bot. Centralbl., viii. (1881) pp. 219-20. 

+ St. Petersburger Naturf. Gesellsch., 1881 (Russian), See Bot. Centralbl., 
viii. (1881) p. 131. 

t{ SB. K. Akad. Wiss. Wien, Ixxxiii. (1881). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 229 


and that the reason of the failure of the ordinary reactions is the 
intimate mixture of the cellulose with a foreign substance. In order 
to eliminate this, it is necessary to treat it for a prolonged period —in 
some cases several weeks—with potash, and then to wash with a weak 
acid, after which the blue colouring with chloriodide of zine is 
obtained. This treatment was successful with Agaricus campestris, 
Polyporus Ribis (?), and fomentarius, the sclerotia of ergot, and some 
lichens ; with Mucor and Saccharomyces it has not hitherto been fully 
successful; with Dedalea quercina the application, in addition, of 
Schultze’s maceration was necessary. 

With regard to the nature of the substance which prevents the 
cellulose-reaction, the author determined, in Dedalea and other 
instances, the presence of suberin, by the formation of insoluble 
cereinic acid or treatment with nitric acid and potassium chloride. 
In the mushroom he believes he has also determined the presence of 
proteinaceous substances. 


“Mal nero” of the Vine.*—The vines in the South of Europe, 
and especially in Sicily, and South Italy, have been attacked, since 
1863, by a disease known as “mal nero,” which has inflicted great 
injury upon them; but its exact nature has not heretofore been 
determined, At the instance of the Italian Government, G. Cugini 
has now undertaken its investigation, and with the following 
results :— 

The presence of the disease is indicated by the appearance, in the 
spring, of black streaks and spots on the branches, leaf-stalks, and 
veins, and on the tendrils and stalks of the branches, penetrating 
internally to the duramen. It must not be confounded with the 
anthracnose (vajolo) caused by Gleosporium ampelophagum (Sphaceloma 
ampelinum). 

The disease is caused by a parasitic fungus, a variety of Sphe- 
ropsis Peckiana Thiim. In the interior of the diseased stems and 
branches was found abundance of a brown mycelium, which de- 
veloped especially in the cambium, and between the epidermis and 
cork-layer. In the parenchymatous tissue of the bark and wood was 
also found a great quantity of a yellowish-brown granulation, the 
exact nature of which was not determined. The particles appear 
to be crystals of calcium tartrate, the result of a hindering effect 
produced by the fungus on the assimilation of the food-materials 
absorbed through the root. They are found chiefly in the roots, leaf- 
stalks, and branches, where the mycelium is comparatively speaking 
absent. 

Roesleria hypogea parasitic on the Vine.{—G. Le Monnier has 
found a disease of the vine closely resembling that caused by 
phylloxera, to be produced by a parasitic fungus which he identifies 
with Roesleria hypogea v. Thiim. But since that genus was founded 
on the special form of the spores (which Le Monnier does not 

* G. Cugini, ‘ Ricerche sul Mal nero della vite.’ 25 pp. (3 pl.). Bologna, 1881. 
See Bot, Centralbl., viii. (1881) p. 147. 

+ Bull. Soc. Sci. Nancy, xiii. (1881) p. 69. See Bot. Centralbl., viii. (1881) 
p. 47. 


230 SUMMARY OF CURRENT RESEARCHES RELATING TO 


confirm), and on the absence of paraphyses, which, however, are 
present, though difficult to make out, he considers that the genus 
must be suppressed, and the species arranged under the old genus 
Vibrissea. 

Didymospheria and Microthelia**—The identity had been 
suggested t by Dr. Rehm of the genus Didymospheria of Pyrenomy- 
cetes with Microthelia of lichens, and the suppression of the former 
in favour of the latter and older name. G. v. Niessl is unable to 
accept this view; but regards the former as a true genus of Pleo- 
spore, a family made up of genera characterized as under :— 

1. Physalospora, Spores (ascospores) one-celled. 

2. Didymospheria. Spores two-celled. 

3. Leptospheria. Spores multicellular, septated transversely 
only, arranged in one or more rows in the asci. 

4. Raphidophora. Spores multicellular, septated transversely, 
arranged in threads or clusters in a straight or coiled bundle in the 
ascl. 

5. Pleospora. Spores multicellular, septated transversely and 
longitudinally. 


Peronosporee and Saprolegniez.{—Professor A. de Bary gives 
a very detailed description of the sexual and non-sexual organs of 
the various species included under the Peronosporeew and Sapro- 
legniez. 

Pythium de Baryanum is much the most widely distributed of 
the Peronosporex, its thallus being very abundant in living tissues, 
and in the intercellular spaces, not only in Crucifere, but in plants 
belonging to widely separated natural orders. It is a true parasite, 
and extremely destructive to the host; but it occurs also in great 
abundance in the soil, in the form of mycelium, resting conidia, and 
oospores. It is characteristic of the species that in the formation of 
the zoosporangia and resting conidia, adjoining portions of the thallus 
are nearly or entirely and permanently deprived of their protoplasm ; 
the emptied portion usually becoming separated off by a septum. 
The resting conidia resemble the zoosporangia in every respect 
except the formation of the neck and of the zoospores. The average 
diameter of the oogonia is 21-24 y, and of the oospores 15-18. As 
soon as the fertilizing tube is formed which carries the contents of 
the antheridium to the oogonium, the protoplasm in the former 
separates into two layers, a denser granular central layer which 
de Bary calls “ gonoplasm,” and a less dense, nearly homogeneous 
parietal layer, the “periplasm.” The former only appears to 
participate in the actual process of impregnation. 

P. vexans de By. occurs in tubers of the potato which have been 
partially destroyed by Phytophthora, and is closely related to, but 
apparently not identical with, P. Equiseti, found by Sadebeck on the 

* Hedwigia, xx. (1881) pp. 161-6. 

+ See this Journal, iii. (1880) p. 314. 

t+ A. de Bary, ‘Beitrage zur Morph. u. Phys. der Pilze,’ Frankfurt a. M. 


1881, pp. 1-71 (6 pls.); and Bot. Ztg. xxxix. (1881) pp. 521-30, 537-44, 553-63, 
569-78, 585-95, 601-9, 617-25 (1 pl.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 231 


prothallium of Hquiseta and on potatoes. The oogonia and oospores 
are smaller than those of P. de Baryanum, the former measuring 
15-18 », the latter 12-15. It also differs in the mode of germi- 
nation, and in the abundant formation of zoospores from the freshly 
formed oospores. It also shows no indication of its thallus penetra- 
ting the living tissue of the host; it is a saprophyte, not a parasite. 

P. megalacanthum nu. sp. is found, along with the first species, on 
cress ; but only on tissue which is already dead, and is hence not a 
true parasite. The zoospores are of comparatively large size, having 
an average diameter of 18-20 yu after coming to rest; and 12-15 or 
more are formed in a zoosporangium. The oogonia are characterized 
by a large number of vertical conical protuberances, averaging about 
one-half the length of the radius of the oogonium. The formation of 
ocgonia and oospores takes place chiefly within the tissue of the host. 
There is a less sharp distinction between gonoplasm and periplasm. 

P. intermedium u. sp. is also saprophytic on Lepidium and 
Amaranthus. The conidia are formed in rows of from 2-5 by 
successive abstriction, in a manner different from that known in any 
other species of Pythium. The author has at present failed to detect 
oogonia and antheridia. 

P. proliferum appears on dead insects floating in water that 
contains alge; it does notattack living plants. This species closely 
resembles P. de Baryanum in its general morphology, and in the size 
of the oogonia and oospores. It is characterized by the successive 
formation of new zoosporangia by a process of prolification. A 
slightly different form, possibly permanently distinct, is named by 
the author P. ferax. 

All the species of Pythium hitherto described have more or less 
globular zoospores; in P. monospermum, reptans, and gracile, the 
zoosporangium is filiform, the zoospores being formed in the terminal 
cell of an ordinary branch of the thallus. 

P. gracile occurs in dead flies, in water that contains alge, and 
can be cultivated on dead plants of Lepidium or Camelina. The 
oogonia are very minute, and are formed only in and between the 
cells of the dead plant. On warm days in summer the oospores are 
mature in from 24—48 hours after fecundation, and remain then for 
months in a resting condition. The other forms with filiform zoo- 
sporangium are exceedingly similar, and perhaps identical, but appear 
to be truly parasitic. 

Associated with the species already described, and especially with 
P. de Baryanum, there is commonly found one with spiny oogonia, 
described by Montagne and Berkeley under the name Artotrogus 
hydnosporus. This is the foundation of Montagne’s genus Artotrogus, 
formed, as de Bary thinks, on insufficient grounds, chiefly from the 
negative character of the absence of zoospores, and he proposes for it 
the name Pythium Artotrogus. ‘The antheridia are never, the oogonia 
rarely, formed from terminal cells of the branch. 

Phytophthora omnivora is a parasite on a large number of healthy 
plants, rapidly killing them, especially in wet seasons, or when 
otherwise well supplied with moisture, and then living as a 


232 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Saprophyte on the dead tissues, or on dead animals. The oogonia 
appear to be produced only under water, and only on some of its 
vegetable hosts. Experiments completely failed to infect the potato 
or tomato with this species, which de Bary identifies with Hartig’s 
P. Fagi, which produces the destructive disease on seedling beeches,* 
with Schenk’s Peronospora Sempervivi, and probably with Cobn’s 
P. Cactorum. This species agrees in all essential points of structure 
with the well-known P. infestans. The conidia or zoosporangia are 
considerably larger than in that species, but vary in size, the 
average length being about 50-60 yu, and the average breadth about 
35 «3; their granular protoplasm is of a darker colour, The ripe 
oogonia are spherical, with a thick, smooth wall, and smaller than 
in most species of Peronospora, about 24-30 w in diameter. They 
are usually terminal, and are produced on lateral swellings or 
branches. In the process of fecundation there is not, as in Pythium, 
the formation of any distinct gonoplasm-layer. This species agrees 
with P. infestans in the peculiarity which distinguishes the latter 
from all others of Peronospora, viz. the successive formation of several 
conidia on one conidiophore. The two species are, however, un- 
doubtedly distinct, and in all probability the unknown oospores of 
P. infestans resemble those of P. omnivora in their smooth surface, 
and in other particulars. Although the name P. Cactorum has the 
claim of priority for this species, de Bary prefers the more descriptive 
P. omnivora. 

In Peronospora the history of development of the sexual organs is 
very similar to that in Phytophthora, There is no evident passage of 
any considerable quantity of protoplasm from the fertilizing tube to 
the oosphere. 

In the species of Saprolegnia belonging to the ferax group (in- 
cluding S. monoica, Thureti, and torulosa), the oogonia are as a rule 
terminal on primary or lateral branches. Here also no passage of 
protoplasm from the fertilizing tube into the oosphere was ever 
observed. The mutual function of the two organs appears to consist 
simply in their close contact, and movements of the protoplasm in 
each of the organs. The tube puts out an appendix which creeps in a 
sinuous course over the surface of the oosphere; it at length loses its 
protoplasm, and finally disappears altogether. When an oogonium 
contains several oospheres, the tube grows from one to another of 
them (except in the case of S. torulosa), and the same process is repeated 
in each case. In S. Thureti and torulosa instances frequently occurred 
of oospores ripening without any contact with the antheridia. 

S. asterophora, distinguished by its spiny oogonium, differs in no 
important point from S. monoica. Here again no opening could be 
detected at any time in the fertilizing tube. Normal oospores are 
occasionally formed without the co-operation of antheridia. 

Achlya prolifera and polyandra resemble one another in all 
essential points. The development of the oogonia presents no 
essential difference from that in Saprolegnia monoica. The most 
important distinction is that in Achlya the protoplasm of the 


* See this Journal, ii. (1879) p. 923. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 233 


oogonium, before and during the rounding off of the oospheres, is 
much more coarsely granular and hence less transparent than in 
Saprolegnia. The oospheres are smaller; their number always two or 
more. No opening of the fertilizing tube is apparent, and its contact 
with the oosphere is less intimate than in Saprolegnia. The oospheres 
sometimes become invested with a cell-wall when the antheridia have 
not put out any tubes. 

De Bary describes a new species A. spinosa, nearly allied to 
A. cornuta, and presenting a very close resemblance to Saprolegnia 
asterophora. It is characterized by the rarity of the production of 
reproductive organs, especially of zoosporangia. Ripe oospores are 
occasionally produced without contact from antheridial tubes. 

Aphanomyces scaber presents no special point of difference from 
the other genera of the family as regards the mode of reproduction. 
The oospores are here also sometimes produced parthenogenetically. 

In all the genera described, with the exception of Achlya, the 
structure of the ripe oospore is the same, having a wall consisting of 
a thicker epispore and a thinner endospore, which encloses a peripheral 
layer of granular protoplasm, interrupted by a clear speck, and 
globules of oil. In Achlya there is no “ fertilization speck.” In all, 
the oospore is often matured without the production of antheridia and 
fertilizing tubes. In Pythiwm, Phytophthora, and Peronospora, there 
is a distinct “periplasm.” In Achlya, when germination begins, the 
globule of oil has altogether the appearance of a granular ball of 
protoplasm. The germinating tube is clothed with a prolongation of 
the innermost layer of the wall. The entire elongated oospore then 
becomes @ zoosporangium; or the germinating tube does not directly 
produce zoospores, but, on reaching a suitable substratum, developes 
into a vegetating thallus of normal size and form, which then produces 
both zoospores and oogonia ; or it may branch and produce several 
zoosporangia. In some species all three modes of germination occur, 
while others are limited to one of them. 

De Bary considers that the Peronosporeew and Saprolegniee must 
be retained as two distinct groups, with this as their essential distinc- 
tion. In the former the oosphere is formed out of a part only of the 
protoplasm of the oogonium, and is fertilized by the evident absorption 
of a portion of the protoplasm which passes out of the antheridium ; 
while in the Saprolegniez the oosphere or oospheres are formed out of 
the entire protoplasm of the oogonium; their actual fecundation by 
contact with the contents of the antheridium has in no case been 
detected, and in some cases certainly does not take place. The 
original Pythium monospermum of Pringsheim does not agree with the 
above character, but no doubt from error of observation. 

The genera will then be arranged as follows :— 

I. Peronosporem. Pythium or Artotrogus (including Cystosiphon 
Cornu), Phytophthora, Peronospora (including Basidiophora Cornu), 
Sclerospora Schrit., Cystopus. 

II. Saproteeniez. Saprolegnia (= Diplanes Leitgeb), Dictyuchus, 
Achlya, Aphanomyces. 

Of the Peronosporeze, Phytophthora comes nearest to the Sapro-~ 


234 SUMMARY OF OURRENT RESEARCHES RELATING TO 


legniew, while Pythium and Cystopus are the most remote from 
them. 

Lagenidium, Myzocytium, Ancylistes Pfitz., and similar forms come 
very near to Pythium, but are distinguished by their production of 
oospores or zygospores, and may be comprehended for the present 
under Pfitzer’s name Ancylistee. Rhipidium and Monoblepharis are 
also nearly related to the Peronosporee and Saprolegniex; the 
position of the former is uncertain, its mode of fecundation not being 
at present accurately known; while the latter genus must form by 
itself the separate group of Monoblepharidee. 


Fungi in Pharmaceutical Solutions.*—O. Binz states that the 
occasional presence of the lower fungi in pharmaceutical solutions is 
due to the presence of free sulphuric acid, which furnishes the sulphur 
without which the albuminoids of the fungi in question could not be 
formed. They withdraw from the sulphuric acid first the oxygen and 
then the sulphur. 


Vegetable Organisms in Human Excrements.{—H. Nothnagel 
describes the microscopic organisms found in upwards of 800 specimens 
of human excrements. 

Some form or other of bacteria was always found whether the 
excrements were normal or pathological. The most abundant were 
spherobacteria or micrococci, and especially Bacterium termo, and 
these were usually present in enormous quantities; when thin and 
watery usually in the rod form, when firmer usually in the globular 
form. All the forms are coloured yellow or yellowish-brown by 
iodine. Bacillus subtilis was also usually found ; as also Saccharomyces, 
-especially in the excrement of infantile diarrhoea ; the most common 
form resembled S. ellipsoideus. 

In addition to these, other forms were found which had not hitherto 
been recognized in the intestines, distinguished by being coloured blue 
by iodine. The largest of these appeared identical with Prazmowski’s 
Clostridium butyricum, the abundance of which was in proportion to the 
amount of vegetable remains in the excrements. Another smaller 
form was apparently either a Clostridium or Hansen’s Mycoderma 
Pasteurianum. 


Saccharomyces apiculatus.t—The first part of E. C. Hansen’s re- 
searches on the physiology and morphology of alcoholic ferments is occu- 
pied with the life-history of Saccharomyces apiculatus, with the special 
object of determining in what form it exists in the periods inter- 
vening between its periodical appearances on ripe fruits, goose- 
berries, cherries, plums, &c., in the summer. The species presents 
special facilities for this purpose, in consequence of its specific 
characters being more distinctly marked than those of any other 
ferment. 


Hansen affirms that S. apiculatus is found in the summer on ripe 


* Wiener Medicinische Presse, 1880. See Bot. Centralbl., viii. (1881) p. 174. 

+ Zeitsch. fiir klin. Med., 1881 (1 pl.). 

t Meddel. fra Carlsberg Labor., 1881, pp. 159-84 (3 pls.). See Bot. Centralbl., 
viii. (1881) p. 6. 


ae - 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 235 


sweet succulent fruits, rarely on unripe fruits or in other localities; 
from these it is spread by the wind. By rain or the falling of the 
fruit it is carried to the ground, where it hibernates, repeating the 
cycle in the next summer. 

S. apiculatus produces two kinds of gemme, the typical citron- 
shaped, and others more or less oval, the former being produced earlier, 
the latter later. Its power of fermenting is much less than that of 
S. cerevisice, producing only one volume of alcohol where that species 
would produce six. It differs from other species of Saccharomyces in 
this respect, that it does not produce invertin, and therefore cannot 
invert saccharose, nor cause alcoholic fermentation in a solution of it. 
It exerts an unfavourable influence on the production of 'S. cerevisic. 


Etiology of Malarial Fevers.*—Dr. G. N. Sternberg was in- 
structed by the National Board of Health (U.S.A.) to repeat the 
- experiments of Klebs and 'Tommasi-Crudeli made near Rome, whereby 
they believed they had discovered Bacillus malaric. 

The author carried out his experiments in the vicinity of New 
Orleans, where a great number of minute alge, including bacteria of 
various forms, are found upon the surface of swamp-mud, as well as 
in the gutters within the city limits. 

Many of these forms may be successfully cultivated in fish-gela- 
tine solution (method of Klebs), and this fluid, previously innocuous, 
was found, as the result of inoculation with the organisms, to acquire 
pathogenic properties obviously due, directly or indirectly, to the 
presence of the bacteria; for, if they are excluded, the fluids may be 
kept indefinitely without undergoing change, and are innocuous when 
injected beneath the skin of a rabbit. 

Some of the organisms from swamp-mud, gutter-water, and human 
saliva were found to be capable of multiplying within the body of a 
living rabbit, and the fluids and organs containing them (blood, 
serum from cellular tissue, spleen, &c.), possess virulent properties. 
In other words, an infectious disease is produced which may be trans- 
mitted from animal to animal by inoculation. There were some 
which closely resembled and, perhaps, are identical with the Bacillus 
malarice ; but there is no satisfactory evidence that these, or any 
other of the bacterial organisms found in such situations, when 
injected beneath the skin of a rabbit, give rise to a malarial fever 
corresponding with the ordinary paludal fevers to which man is 
subject. 

The evidence upon which Klebs and Tommasi-Crudeli have based 
their claim of the discovery of a Bacillus malarie cannot, the author 
considers, be accepted as sufficient ; (a) because in their experiments 
and in his own the temperature-curve in the rabbits operated upon 
in no case exhibited a marked and distinctive paroxysmal character ; 
(b) because healthy rabbits sometimes exhibit diurnal variations of 
temperature (resulting apparently from changes in the external 
temperature), as marked as those shown in their charts ; (c) because 
changes in the spleen such as they describe are not evidence of death 


* ‘National Board of Health Bulletin,’ Supplement No. 14. Washington, 
23rd July, 1881. 11 pp. and 4 pls. 


236 SUMMARY OF CURRENT RESEARCHES RELATING TO 


from malarial fever, inasmuch as similar changes occur in the spleens 
of rabbits dead from septicemia produced by the subcutaneous 
injection of human saliva; (d) because the presence of dark-coloured 
pigment in the spleen cannot be taken as evidence of death from 
malarial fever, inasmuch as this is frequently found in the spleen of 
septiczemic rabbits. 

While, however, the evidence upon which Klebs and Tommasi- 
Crudeli have based their claim to a discovery is not satisfactory, and 
their conclusions are shown not to be well founded, there is nothing in 
Dr. Sternberg’s researches to indicate that the so-called Bacillus 
malarie, or some other of the minute organisms associated with it, 
is not the active agent in the causation of malarial fevers in man. 
On the other hand, there are many circumstances in favour of the 
hypothesis that the etiology of these fevers is connected, directly 
or indirectly, with the presence of these organisms or their germs in 
the air and water of malarial localities. 

The truth or falsity of this hypothesis can only be settled by 
extended experimental investigations ; and while further experiments 
upon animals may lead to more definite results, it seems probable that 
the experimentum crucis must be made upon man himself, isolating 
and cultivating the various organisms found in malarial localities, and 
experimentally investigating the physiological action of each when 
taken into the stomach or respired in a dry state by healthy indi- 
viduals. The converse method should also be tried of studying the 
bacterial organisms found in the mouth and alimentary canal of persons 
suffering from malarial fever, compared with the common forms found 
in the same situation in the healthy state. 


Aktinomykosis, a new Fungoid Cattle-Disease.* — Under the 
name Aktinomykosis or Strahlenpilzerkrankung, Johne describes an 
infectious disease which attacks the tongue, throat, &c., of cattle, and 
which he attributes to a hitherto undescribed bacterial organism to 
which he gives the name Aktinomyces. The author is not able to 
assign a systematic position to this organism. It commences with an 
unseptated mycelium, probably originating from micrococci, which 
swell up into pear- or club-shaped conidia. When collected into 
masses it not unfrequently becomes hard and calcified. 


Infection by Symptomatic Anthrax.j—Messrs. Arloing, Cornevin 
and Thomas give some results of their intravenous method of inocula- 
tion { applied under the authority of the French Government, and of 
other methods which they have tested. Of these other methods (1) that 
by the digestive passages has not hitherto been found to produce the 
disease ; (2) that by the respiratory cavities causes a merely abortive 
malady ; (3) that by injection into the connective tissue (either dermal, 
subcutaneous, or intramuscular) of infinitesimal quantities of virus 
results in abortive symptoms ; with a medium dose, a trifling local dis- 
turbance is set up, but more lasting general effects are also produced 

* Deutsch. Zeitschr. fiir Thiermed., viii. (1881) pp. 143-92 (3 pls.). See Bot. 
Centralbl., vii. (1881) pp. 338. 


+ Comptes Rendus, xcii. (1881) pp. 1246-9. 
{ See this Journal, i. (1881) p. 95. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 237 


in the form of one or more symptomatic tumours at points remote from 
the place of inoculation; with a very strong dose a tumour imme- 
diately appears at this point, the general condition of the patient 
becomes rapidly serious, and if life lasts sufficiently long, one or more 
tumours may arise in different parts of the muscles. (4) The results 
of the intravenous process of injection similarly differ with the amount 
of virus employed. With a minute quantity general disturbances are 
produced, which disappear in two or three days, leaving the subject 
proof against the effects of further inoculation; this is caused by 
an abortion of the anthrax. With a considerable dose, symptomatic 
anthrax is fully developed, and tumours appear, invariably causing 
death. 

These different modes in which the poison may be seen to act are 
thus explained. In the case in which intravenous injection is not fatal 
the bacterium probably multiplies in the blood, but is prevented by 
the endothelium of the vessels from entering the connective tissue. 
The serious consequences which always follow introduction of the 
poison into the latter tissue—extending to the production of a local 
tumour, even after a preventive inoculation by intravenous injection— 
show this to be really the point at which the virus attacks the system. 
When tumours follow intravenous injection, the bacterium must have 
passed in some way into the connective tissue, whether by rupture of 
other coats or otherwise. The abortive result of inoculation by way 
of the respiratory system, as well as by way of the veins, is due to the 
same cause, viz. the penetration into the blood of the bacterium 
through the lining-epithelium and its development in this harmless 
position. 

A short account of some public experiments performed by the 
same three investigators at Lyons is given by Bouley.* The first 
series were intended to show immunity against symptomatic anthrax 
produced by previous intravenous inoculations at different periods. 
Thus a ram inoculated in the thigh with 5 cc. of the virus died in two 
days, but a calf, vaccinated fourteen months previously by intravenous 
injection, showed not the smallest sign of evil effects after injection of 
1 mm. in the same manner as in the former case ; the same immunity 
was exhibited by another calf inoculated with 5 mm. eleven months 
after vaccination ; so also with a calf sixteen days old whose mother 
had been inoculated twenty-seven days after the commencement of 
gestation (six months before the birth of the calf), An ewe, vaccinated 
fifteen days previously by injection into the trachea, behaved similarly 
on injection of 5 mm. into the thigh. A second series of experiments 
showed the refractory behaviour of certain animals towards the disease ; 
thus subcutaneous and intramuscular injections produced no effects 
on a pig, a white rat, a dog, and a rabbit, but the same operation 
performed at the same time killed a six months’ calf. 

The method of vaccination here adopted differs from that employed 
by Pasteur against the other form of anthrax (bacteridian anthrax) in 
not employing a mitigated form of the virus, but introducing the virus 
in its natural condition into surroundings (i.e. the blood-vessels) not so 


* Comptes Rendus, xcii. (1881) pp. 1383-7. 


238 SUMMARY OF CURRENT RESEARCHES RELATING TO 


favourable to its development as other parts of the body. The value 
of the method has been proved by the subjection of 244 animals to its 
action. 


Experiments on Pasteur’s Method of Anthrax-Vaccination. *— 
In his own name and the names of Messrs. Chamberland and Roux, 
L. Pasteur gives a summary report of a series of experiments made 
by them in May and June 1881, near Melun (Seine-et-Marne), at the 
request of the Agricultural Society of that place, in order to 
demonstrate the vaccinating power of a modified form of anthrax 
virus, as already described. 

Fifty-eight sheep, of different breeds, ages, and sexes, two goats, 
eight cows, a bullock, and a bull having been placed at their disposal, 
they set aside 10 of the sheep and inoculated 24 of the remaining 50, 
together with 1 goat and 6 cows, with a mitigated form of anthrax 
virus, and then, after 12 days, with a stronger solution. After a 
further interval of 14 days, the 31 vaccinated animals, together with 
the 24 sheep, 1 goat, and 4 oxen still remaining unvaccinated, were 
inoculated with a very deadly form of anthrax virus, vaccination being 
carried out alternately on vaccinated and unvaccinated animals. The 
company, including numerous local and departmental authorities and 
professional men, were assembled after two days to witness the results of 
the experiments. All the subjects of the preliminary inoculation were 
found, to all appearance, in good health (one died subsequently from 
a cause other than anthrax), but of the others, 21 sheep and the goat 
had already perished from the disease, 2 more sheep died in the 
presence of the spectators, and the twenty-fourth died at the close of 
the day. None of the oxen died, but all developed large swellings 
round the point of inoculation, and their temperature rose 3°, A large 
number of those present expressed their conviction of the importance 
of the method adopted. 

Professor Milne Edwards ¢ has compared some of the facts brought 
forward by M. Pasteur with the phenomena of alternation of generations 
exhibited by some Hydrozoa, and suggested that experiments should 
be made to ascertain whether in this case, as in that of the septic 
organisms described by M. Pasteur, variations in the temperature or in 
the amount of air dissolved in the water, might be made to produce 
whichever stage of these animals might be required. 

Some experiments, as reported by Bouley,§ were also made publicly 
at Chartres, with the view of testing the principles laid down by 
M. Pasteur, and supported by his experiments at Melun. They differ 
from those experiments in employing infected blood for the inocula- 
tions instead of artificial growths of the virus. Thus 19 sheep already 
inoculated, together with 16 which had not been inoculated, were all 
injected with half a syringeful each of a mixture of blood and splenic 
pulp taken from a sheep which had just died of anthrax ; 15 of the 16 
unvaccinated sheep died within 3 days of the operation ; the 19 which 


* Comptes Rendus, xcii. (1881) pp. 1378-83. 
+ See this Journal, i. (1881) p. 499, &e. 

+t Comptes Rendus, xcii. (1881) p. 1383. 

§ Ibid., xciii. (1881) pp. 190-2. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 239 


had been vaccinated showed no sign of ill-health. The method of 
vaccination is thus proved to be as efficacious against virus produced 
naturally as against that produced by artificial means. 


Duration of Immunity from Anthrax.*—H. Toussaint bears 
testimony to the finality of M. Pasteur’s recent investigations on this 
subject. He draws attention to one or two minor points yet unsolved, 
viz. the duration of the immunity against the disease, and the power 
of inheriting this immunity which is possessed by animals. The 
duration is said to vary directly with the severity of the first attack, 
and inversely with the resistance of the animal to the disease; for 
certain lambs and ewes which had suffered severely from the effects 
of a first inoculation had preserved their immunity up to the time of 
writing (12 months), and the ewes had transmitted it to their off- 
spring; while of certain 20-month lambs and old ewes which were 
first vaccinated with a weaker virus than in the preceding case, and 
which had resisted an inoculation made a month later, some of the 
ewes were overcome by the effects of a third inoculation made four 
months later, while the 20-month lambs survived. The fact of in- 
heritance of the immunity is shown by the absence of any evil results 
of inoculation of lambs of one month which were born of vaccinated 
ewes; this is a genuine case of inheritance, which cannot be said 
with equal truth of lambs born of parents inoculated during gestation, 
for in this case the lamb in utero forms practically part of its parent. 


New Method of Vaccination for Fowl-cholera.j,—H. Toussaint 
supplements M. Pasteur’s researches in this subject by experiments 
showing new methods of mitigating the virulence of the poison, 
and confirming his own previous opinion as to the identity of septi- 
cemia and fowl-cholera. In one case rabbits inoculated with blood 
infected with anthrax died in 7 or 8 hours of septicemia, pigeons died 
from its effects in from 1 to 4 or 5 days, fowls inoculated from the 
pigeons also in from 1 to 4 or 5 days. The bacterium of the disease 
exactly resembles that of fowl-cholera, and all the symptoms and 
lesions are precisely similar with both the diseases. In another set of 
experiments, consisting in inoculating fowls directly with blood from 
rabbits which had died of septiceemia, the fowls were not killed, but 
proved to have undergone a vaccinating action, being afterwards proof 
against both fowl-cholera and septicemia. ‘To secure this result it is 
only necessary to vaccinate at the end of the wing. M. Toussaint is 
inclined to explain the fowl-cholera as produced by certain bacteria 
whose development is favoured by the presence of putrefying organie 
matter. 


Rabies.t—This obscure subject has been now approached by the 
famous experimenter on germ-diseases, L. Pasteur, in conjunction 
with Messrs. Chamberland, Roux, and Thuillier. The view long 
supported by Dr. Duboué, that the central nervous system, and above 
all the medulla oblongata connecting the spinal cord with the cere- 


* Comptes Rendus, xciii. (1881) pp. 163-4. 
+ Ibid., pp. 219-21. 
¢ Ibid., xcii. (1881) pp. 1259-60. 


240 SUMMARY OF CURRENT RESEARCHES RELATING TO 


brum and cerebellum, is the seat of the development of the disease, 
had been disputed by Prof. V. Galtier, who found indications of virus 
only in the lingual glands and on the mucous membrane of the mouth 
and pharynx, and not in the above-named parts of dogs affected with 
the disease. Pasteur and his companions have, however, often suc- 
cessfully inoculated the medulla oblongata, the cerebro-spinal fluid, 
and the frontal portion of one of the hemispheres. The period of 
incubation before manifestation of its effects has hitherto been found to 
be uncertain, and often long, but this period can now be diminished 
by inoculating the surface of the brain directly with pure brain sub- 
stance removed from a mad dog: in this case, the symptoms of 
madness, either under its silent or furious form, appear within a fort- 
night of the operation, and death ensues in less than three weeks 
from the same date. This method has never—as in so many other 
cases—failed in producing the disease. 

The results of some experiments * with the active elements of 
rabies have led Prof. Galtier to some important conclusions. Six 
sheep and four rabbits inoculated at different times with this poison 
by hypodermic injection all died from its effects; while out of nine 
sheep and one goat inoculated by intravenous injection none succumbed, 
but on the contrary, all successfully resisted the effects of subsequent 
inoculations. Of five rabbits which received as a draught some saliva 
infected with virus and mixed with water, only two died. The con- 
clusions deduced are:—(1) Intravenous injection of the poison of 
rabies into sheep does not produce the disease, but seems to confer 
immunity against it; (2) introduction of the poison into the digestive 
organs is fraught with danger. Galtier has reasons for suspecting 
that intravenous injection, practised the day following a bite or 
inoculation, or even the next day, will prove effectual in warding off 
the malady. 

Lichenes. 

Nutrition of Lichens.j;—G. Egeling disputes the statement that 
when lichens grow on apparently smooth surfaces, as quartz, glass, 
&ec., they are true “epiphytes.” On even the smoothest surface, 
there are always irregularities which allow of the accumulation of 
dust ; and from the substances which collect in this way, the lichen 
obtains its nutriment, until it is able to decompose the hardest and 
smoothest substances, even glass or oxide of iron. 


Thallus of Usnea articulata.t—According to A. Jatta, the thallus 
of this lichen consists of three distinct layers, viz. (1) a central, 
continuous, compact, elastic, very resistant tissue, the medullary layer ; 
(2) a much laxer and readily distinguishable tissue, composed of 
branched hyphe and gonidia, the gonidiferous layer; and (3) a 
membranous sheath, very delicate and almost inelastic, the cuticular 
layer. The interrupted or jointed thallus, characteristic of the species, 
is the result of the unrolling of the spiral of the medullary filaments, 
which causes their rapid elongation, in contrast to the very slight 

* Comptes Rendus, xciii. (1881) pp. 284-5. 


+ Oesterr. Bot, Zeitschr., xxxi. (1881) pp. 323-4. 
t Nuoy. Giorn. Bot. Ital., xiv. (1882) pp. 53-9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 241 


elasticity of the cuticular layer and the looseness of the gonidiferous 
layer. 

The author objects to the ordinary term “ gonidial layer” as 
applied to lichens, seeing there is no distinct layer composed entirely 
of gonidia. The gonidia of Usnea articulata are of the form referred 
by Bornet to Protococcus. In the older part of the thallus they are 
perfectly free from hyphe, and are grouped in various ways in the 
outer part of the gonidiferous layer; but in the younger part of 
the thallus the hyphe are composed of shorter cells and assume a 
more contracted appearance, and the gonidia are often to be found 
adhering to their apices. 


Algee. 


Symbiosis of Lower Animals with Plants.*—The relations which 
subsist between the different organisms which live upon, or within 
each other, are very various; for the one, in its capacity of parasite 
or companion or guest of the other, exercises on its host an influence 
which is in some cases injurious, and in others advantageous to the 
vital conditions of the latter. Many instances of this life in 
common, or symbiosis, are known among animals as well as plants, 
but the cases of symbiosis between animals and plants are less well 
known; and in regard to these, K. Brandt has made some interesting 
communications to the Physiological Society of Berlin, of which the 
following is an extract. 

Chlorophyll, which occurs in all plants except the Fungi, is 
known to occur in the animal kingdom also—in Rhizopoda, ciliate 
Infusoria, fresh-water Sponges, the tentaculate Polypes, and many 
marine and fresh-water Turbellaria. In all these the chlorophyll 
is present in the form of sharply defined, oval, or round granules, 
identical with its form in plants. Three contradictory views have 
been held with regard to the presence in animals of chlorophyll: 
(1) that the green particles are true chlorophyll-granules, (2) that 
they are not produced by the animals themselves, but must be con- 
sidered as parasites, (3) that in the case of the Protozoa, at any rate, 
the green masses are merely parts of vegetable organisms which 
have been absorbed after being submitted to digestion. Direct 
observation has not yet decided the question. In his ‘ Natural 
Conditions of Animal Existence, Semper gives a critical sketch of 
the investigations which have been made, and comes to the conclusion 
that the green particles should be regarded either as endogenous 
products of the animal, or as commensals, and he considers the latter 
opinion the most probable one. The author has accordingly made ex- 
periments with microchemical reagents in order to determine whether 
the green bodies consist simply of chlorophyll combined with a 
fundamental substance, or whether they contain colourless protoplasm 
as well, and whether they have a nucleus, and are invested by a 
cellulose membrane, also whether they are physiologically inde- 
pendent, or continue to live after the death of the animals in which 


* Verhandl. Physiol. Ges. Berlin, 1881-2, p. 22. Cf. Naturforscher, xv. 
(1882) pp. 15-17; and Rey. Internat. Sci. Biol., v. (1882) p. 149-52. 
Ser. 2.— Vor. II. R 


242 SUMMARY OF CURRENT RESEARCHES RELATING TO 


they occur, and whether it is possible to infect an animal which has 
no chlorophyll, by means of a fragment of one which does contain it. 

The morphological investigations were carried out upon Hydra, 
Spongilla, a fresh-water Planarian, and a variety of Infusoria. The 
green bodies were isolated by crushing the animals and were then 
examined with high powers, and it was found that they are not of a 
uniform colour like the chlorophyll-bodies of plants, but contain 
hyaline protoplasm. Treatment with hematoxylin always reveals 
a definite cell-nucleus, and the same is the case if the animals are first 
killed by 0-2 per cent. chromic acid, or 1 per cent. per-osmic acid, then 
freed from chlorophyll by alcohol, and finally treated with solution 
of hematoxylin. These characters prove that what have been 
described as chlorophyll-corpuscles in animals are really unicellular 
beings, morphologically independent, which Brandt describes as two 
new genera of Alga, Zoochlorella, and Zooxanthella, with several 
species ; the first-named are green, and are met with in animals 
belonging to the Protozoa, the Sponges, the Hydrozoa and the 
Turbellaria; the second are yellow, and are found in some Radiolaria, 
certain Hydrozoa, and some Actinie. 

Their physiological, as well as their morphological independence 
can also be established. Thus, if specimens of Zodchlorella are 
isolated, they do not die, but live for some days, and even weeks, and 
when exposed to the light are able to develope starch-grains. In- 
oculation-experiments show besides that the species of Zoochlorella 
also differ physiologically znter se. Green bodies isolated from Spon- 
gilla and brought into contact with Infusoria devoid of chlorophyll, 
although in many cases taken in, were unable to persist in the latter 
animals; they were either digested or expelled without undergoing 
any alteration. On the other hand, Infusoria devoid of chlorophyll 
were successfully inoculated by Zoochlorelle from a dead Hydra 
viridis. Many Ciliata, absolutely without green corpuscles, absorbed 
the parasitic forms of the Hydra, and kept them for a long period. 

With regard to the question of the origin of the chlorophyll, 
Brandt concludes that the animal organisms do not themselves 
produce it, it being found nowhere but in true plants, so that when 
met with in animals, it owes its existence to parasites. He describes 
in the following terms the results to which his experiments have led 
him: “In making use of the expression ‘ parasites, for the yellow 
and green alge, I have been actuated by the desire of abbreviation, 
as well as by the fact that morphologically the alge have almost the 
appearance of parasites on animals. Physiologically, they cannot be 
regarded as parasites. They cannot be compared with the parasitic 
fungi, the Teenie, &c., for these derive their subsistence from their 
hosts alone, form no nutrient matter themselves, and give out still 
less, while the species of Zoochlorella and Zooxanthella have the power 
of producing organic materials (water and carbonic acid) themselves, 
in the same way as true plants. At first sight, one would expect 
them not to remove organic matters from their host, but rather to 
supply them to the latter. What, however, really takes place, and to 
a very large extent, is shown by the following observations :— 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 243 


“(1) In carefully examining large colonies of Radiolaria, I have 
not found, either in their gelatinous matter or in its neighbourhood, 
any foreign bodies which had undergone digestion. Inasmuch as they 
require, by reason of their very considerable bulk, large quantities of 
nourishment, and as they are absolutely destitute of any power of 
manufacturing organic substances out of water, carbonic acid, and 
ammonia, they cannot be kept alive by any other means than the 
yellow cells which they harbour in large quantities. (2) I have been 
able to keep the colonies with ease by placing them in well-filtered 
sea-water : under these conditions they are deprived of all possibility 
of nourishing themselves, like true animals, with solid organic 
substances. (3) I have kept Spongilla in filtered river-water for the 
same length of time. Even when the water has been filtered daily, 
they have flourished wonderfully. But whenever the vessel was 
placed in a half-darkened spot, they regularly died. Light is abso- 
‘ Ilutely necessary to them. 

“ This proves, then, that Zooxanthella and Zoochlorella contribute to 
the support of their hosts. As long as the animals contain but few or 
no green or yellow cells, they are nourished like true animals, by the 
absorption of solid organic matcrials; as soon as they contain a 
sufficient amount of alge, they are nourished like true plants, by 
assimilation of inorganic materials. They ought to resume their 
animal mode of nourishment when the alge withhold their functions, 
in the absence of light. They perish if they do not then again adapt 
themselves to the mode of alimentation which properly belongs to 
them. 

“The researches of botanists have brought to light two different 
ways in which alge may live in connection with other vegetable 
organisms. Firstly, alge are found living like “lodgers” in other 
chlorophyllaceous plants. Secondly, according to Schwendener, they 
live in companionship with fungi, and with them form lichens. In 
the first case the parasitic alge usually behave indifferently in relation 
to the conditions of assimilation adopted by their hosts. The alge 
are nourished like the plants in which they live, by assimilation of 
organic matter. In the lichens, the alge furnish the nutritive matter 
to the fungi, which live parasitically upon them. The alge manu- 
facture organic substances out of inorganic substances, and the fungi 
utilize them. . 

“The association of alge and animals is an analogous case, but 
nevertheless differs from it. In the green and yellow animals the 
same phenomenon usually occurs; the alge manufacture organic 
substances from inorganic substances, and the animals make use 
of them. But while in the lichens we find true parasites (fungi) 
associated with alge, in the green and yellow animals we find 
a symbiosis of algw with independent animals, habituated to an 
independent existence. The animals (Phytozoa as they may be 
termed) renounce their independent life and allow themselves to be 
supported entirely by their parasites, when once the green or yellow 
alge have entered their tissues and have multiplied there sufficiently. 
They absorb no more solid organic substances, although they are 

R 2 


244 SUMMARY OF CURRENT RESEARCHES RELATING TO 


perfectly able to do so, but are entirely comparable, from the morpho- 
logical point of view, to animals devoid of chlorophyll. This life of 
alge in common with animals is one of the strangest things which 
can be conceived. Morphologically it is the alge which are the 
parasites, but physiologically the animals.” 


“Yellow Cells” of Radiolarians and Celenterates.*—Mr. P. 
Geddes was also simultaneously (and independently) working at the 
same subject as that which had engaged Herr Brandt’s attention 
(forming the subject of the preceding note), and in a communication 
to the Royal Society of Edinburgh he deals with the vexed question 
as to the nature of the “ yellow cells” also, presenting an interesting 
aspect of the economic inter-relations of the animal and vegetable 
kingdoms, 

The author’s researches on animal chlorophyll had already shown 
that such animals as Convoluta, Hydra, and Spongilla vegetated by 
their own intrinsic chlorophyll; and he now shows that certain Radio- 
larians and Celenterates vegetate, as he terms it, “by proxy, by 
rearing copious crops of Algz in their own tissues, and profiting by 
their vital activities.” Cienkowski and others have already contended 
that the “yellow cells” in question were alge, for the reason, among 
others, that they continued to live and multiply long after the death 
of the animal, but the subject was obscured by contradictions. After 
repeating the observations of Cienkowski on the Radiolarian yellow 
cells, the author undertook an independent examination, which 
established their character as true alge. Not only is their mode of 
division thoroughly algoid, but starch, as described by Haeckel, is 
invariably present. The cell-wall is of true vegetable cellulose, and 
the yellow colouring matter is the same as that of diatoms. In Velella, 
in sea anemones, and in a Rhizostome Medusa (Cassiopeia borbonica), 
similar organisms were found. 

Alluding to the methods of examination, Mr. Geddes says that the 
failures of former observers in obtaining these reactions have been 
simply due to neglect of the ordinary botanical precautions. Such 
reactions will not succeed until the animal tissue has been preserved 
in alcohol and macerated for some hours in a weak solution of caustic 
potash. Then, after neutralizing the alkali by means of dilute acetic 
acid, and adding a weak solution of iodine, followed by strong sul- 
phuric acid, the presence of starch and cellulose can be successively 
demonstrated in the same preparation. “Thus, then, the chemical 
composition, as well as the structure and mode of division, of these 
yellow cells are those of unicellular alge. I therefore propose for 
this alga the generic name of Philozoon, and distinguish four species 
differing slightly in size, tint, mode of division, &c., to which the 
names of P. radiolariarum, P. siphonophorum, P. actiniarum, and P. 
medusarum, according to their habitat, may be conveniently applied.” 

The mode of life and functions of the organisms are fully dealt 
with. Reminding us that the colourless cells of a plant share the 
starch formed by the green cells, Mr. Geddes urges that it is impos- 


* Nature, xxv. (1882) pp. 303-5, 


——— 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 245 


sible to doubt that when the vegetable cell dissolves its own starch, 
some must needs pass out by osmosis into the closely enveloping pro- 
toplasm of the surrounding animal cell, which possesses abundance of 
amylolytic ferment. Further, the nutritive functions of the animal 
gain by digesting the Philozoon at its death. On the other hand, the 
carbonic acid and nitrogenous waste produced by the animal cell are 
necessities of life to the alga, which in removing them performs an 
intracellular renal function. Yet further, during sunlight the alga 
constantly evolves nascent oxygen into the surrounding animal proto- 
plasm, and so we have foreign vegetable chlorophyll performing the 
respiratory functions of native animal hemoglobin, and the resem- 
blance becomes closer when we bear in mind that hemoglobin fre- 
quently lies as a stationary deposit in some tissues like the tongue of 
certain molluscs and the nerve-cord of Aphrodite and Nemerteans. 

Thus, then, “for a vegetable cell no more ideal existence can be 
' imagined than that within the body of an animal cell of sufficient 
active vitality to manure it with abundance of carbonic anhydride and 
nitrogenous waste, yet of sufficient transparency to allow the free 
entrance of the necessary light. And conversely for an animal cell 
there can be no more ideal existence than to contain a sufficient 
number of vegetable cells, constantly removing its waste products, 
supplying it with starch and oxygen, and being digestible after 
death. . . . In short, we have here economic inter-relations of 
the animal and the vegetable world reduced to the simplest and closest 
conceivable form.” 

That this is no mere case of parasitism is further proved by the 
fact that it is exactly those animals containing the alge (“animal 
lichens,” as the author suggests they might not unfairly be called) 
which show exceptional success in the struggle for existence, instead 
_of the weakened state to be found in the host of a parasite. They are 
not only far more abundant, but are capable of enduring greater hard- 
ships than their less fortunate allies. 

Mr. G. Murray * considers that ‘“‘ to botanists these investigations 
bear a very peculiar interest. No nearer analogue to this ‘ consortism,’ 
if it may be called so, of the animal and the vegetable (algal) cell can 
be found than in that of the fungal and algal cells of the lichens. It is 
so apparent throughout that it is needless to enter into a detailed com- 
parison. One point in the analogy, however, is noteworthy. The 
young gonophores of Velella which bud off from the parent colony, 
start in life with a provision of Philozoon. One cannot but be forcibly 
reminded by this of the function of the hymenial-gonidia of such 
lichens as Dermatocarpon, Polyblastia, &c., as described by Professor 
Stahl. The hymenial-gonidia, which are the offspring of the thallus- 
gonidia, are carried up in the formation of the apothecia, and are cast 
out along with the spores. Falling in the same neighbourhood, the 
spores, on germinating, enclose with their filaments the hymenial- 
gonidia, which ultimately become the thallus-gonidia of the new 
lichen. The fact that among these animals the most closely allied to 
each other morphologically differ thus widely physiologically, bears 


* ¢ Academy,’ No. 508 (1882) p. 67, 


246 SUMMARY OF CURRENT RESEARCHES RELATING TO 


comparison with the near relations of the fungal parts of the lichens 
with the other ascomycetous fungi.” 


Cooke’s British Fresh-water Alge.—The existing books on British 
fresh-water Algae are so much out of date that a new one will be very 
welcome to algologists and microscopists. The first part of Dr. M. 
C. Cooke’s work is now published, and contains the Palmellaces with 
11 coloured plates and 32 pages of text, and is intended to be 
followed by part 2, the Protococcacee and Volvocineex, and part 3, 
the Zygnemacez. The Desmidiee and Diatomacez are not intended 
to be included. 


Diatoms in thin Rock Sections.—At p. 507 of Vol. I. (1881) 
we gave an account of a careful study of diatoms from the 
tolerably hard diatom-rock of Nykjébing in Jutland, made by 
W. Prinz from transverse sections of three species :—Coscinodiscus 
oculus-iridis, C. excentricus, and Trinacria regina. In the first two 
instances he obtained exceedingly good demonstrations of the encasing 
of one valve in the other, as also of the various thickness of the valves 
at different places. In C. oculus-iridis he found the hexagonal honey- 
comb-like meshes to have an opening at the base, the inner cell-layer 
having a circular perforation in the middle of each cell. In Trinacria 
regina he found the small round dots which cover the entire valve to 
correspond to canals which completely perforate the thickness of the 
valve. Whether this is so also in C. excentricus could not be deter- 
mined with certainty, in consequence of the minuteness of the dots. 

Prinz’s observations differ from those of Fliigel, O. Miller, and 
Green to this extent, that these latter did not observe an actual per- 
foration of the inner layer of the valve, by which the cell-contents 
might altogether pass out. O. Miiller’s observations on Triceratium 
Favus were founded on an ingenious method of flooding. In this 
species and its allies, including Biddulphia reticulata, the inner layer 
of the valve is completely covered by radial rows of fine dots, which are 
nowhere wanting, and which exclude the presence of larger openings. 

It might be assumed that these small dots correspond to canals 
which perforate the inner layer; but A. Grunow states* that he 
has examined very large specimens of the variety sewangularis of 
this species, in which this layer was so thick that it was possible, by 
focussing, to detect the radiating dots on the inner side, and on the 
outer side irregularly disposed short spines at the base of the honey- 
comb-like cells, the walls of which were thickened above and some- 
times elongated into a spine at the corners. Similar structures occur 
in Triceratium Favus and in Coscinodiscus, while T. consimile Green, 
which closely resembles the former, has exactly the structure of 
C. oculus-iridis, In the last-named species a circular depression is 
found in the inner layer of the valve, but no perforation. At these 
depressions the valve is very thin, so that it may be completely 
broken through there by boiling or in other ways. But an “ incontro- 
vertible proof” that there is no actual perforation is afforded by the 
closely allied species C. Asteromphalus, connected with it by inter- 


* Bot. Centralbl., viii, (1881) p. 354. 


a. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 247 


mediate forms. The inner side of the valve is here covered with 
small dots or depressions, which form a circle of larger dots at the 
margin of the meshes, gradually diminishing in size and becoming 
scarcely visible towards the interior, but always covering the whole 
of the base of the meshes. On closer focussing, these minute dots 
disappear, and appear to be the depressions taken by Prinz for per- 
forations. In C. gigas there are found also in the middle only small 
round depressions which are surrounded towards the margin by a net- 
work projecting outwards, so that this species has internally the struc- 
ture of the punctured forms, externally that of C. oculus-iridis, radiatus, 
and similar species. In Trinacria regina the depressions always 
penetrate very deep, as is the case in many diatoms; but at the base 
of the depressions is a smaller indentation which, when highly mag- 
nified, is very clearly seen in the middle of the pore, as occurs again 
in many diatoms. Grunow has examined a large specimen of this 
species, in which a further much more delicate and narrower puncta- 
tion was visible, apparently on the inner surface of the valves. The 
transverse section which Prinz draws of C. excentricus (or more 
probably of C. symbolophora) appears, however, to be correct ; and the 
pore canals are here mostly represented as not completely reaching 
the inner surface of the valve. If these depressions permit endosmose 
through them, their thin inner wall can be perforated only by canals 
so delicate that they are invisible to the highest powers. Grunow 
promises a treatise on this difficult subject. 


Fineness of Striation as a Specific Character of Diatoms.*— 
Prof. H. L. Smith comments upon the paper of Count Castracane on 
this subject,f in which, it will be remembered, he arrived at the 
conclusion that “the strize and their fineness are a quality of specific 
importance.” 

Prof. Smith says :—‘In a few words appended to the translation 
of the paper, Mr. Kitton, the well-known English diatomist, criticises 
Count Castracane’s conclusions, and indicates the mistakes of the 
Count himself in his attempt to make these measurements, which he 
deems of specific performance. The conclusion of the Count, how- 
ever, will be heartily welcomed by ‘species-mongers,’ inasmuch as 
one need have little fear in being able to sustain the claim to n. sp. if 
allowed to fall back on striation as the test, for who shall decide? 
Not every one has at command the elaborate apparatus used by Count 
Castracane for determining the number of striz. Photographs of 
each diatom, projections on a large scale, &c., seem to be con- 
sidered by him as the only trustworthy method; a method of such 
exactness that it ‘enables him to disagree with microscopists of in- 
contestable authority.’ For Count Castracane personally, and as a 
correspondent and a thoroughly conscientious, hard-working diatom 
student, I have the highest respect, but Iam sorry that he has felt 
himself obliged to adopt so pernicious a view, as it seems to me. The 
Diatomacex belong to the vegetable world, and the principles governing 


* Amer. Mon. Mier. Journ., ii. (1881) pp, 221-3. 
+ See this Journal, i. (1881) p. 787. 


248 SUMMARY OF CURRENT RESEARCHES RELATING TO 


their classification and arrangement need not be very different from 
those accepted for other portions of the vegetable kingdom. It would 
seem that with as much propriety one might consider the number of 
granules on a Staurastrum, or strie on the frond of a Closterium, of 
specific importance; or the number of fibres in a given space of a 
specimen of pine or oak, of value in determination of species. I 
venture the assertion, that if one were to show to the distinguished 

-microscopist who has advocated this view of the importance of fineness 
of striation, a'slide of diatoms, and request him to say what they were, 
he would name them all, correctly too, and never once resort to 
measurement of striation to do so. Now, if this can be done, and it 
is done every day by experienced microscopists, what is the necessity 
of bringing in an element which most students of the Diatomacez 
consider very variable and exceedingly difficult to determine. I would 
not have it understood, by what I have said, that I consider striation 
as of no importance; in conjunction with other things, it has a certain 
value, but at best only secondary. 

“T do not suppose that Count Castracane would for a moment 
assert that Stauwroneis Pheenicenteron, e.g., has the same number of 
strie in *001 of an inch as Stauroneis gracilis, and yet I have fre- 
quently found the latter conjugating, and the sporangial frustule 
is 8. Phenicenteron. The sporangial frustules of the diatoms are 
notoriously more coarsely marked than the parent frustules. There 
are a great many species of diatoms, belonging to the N. prima group, 
which really pass into each other so gradually that, even by the help 
of striation, it is difficult to distinguish them; N. affinis produces, by 
conjugation, true NV. prima, and I have even observed the large frus- 
tules of the latter again producing monsters, by conjugation, far more 
coarsely marked than the parent frustules. Shall we consider the 
sporangial form as one species, and the parent form another ? 

“T have before me now a slide of Gomphonema olivaceum containing 
myriads of frustules, many conjugating, and some with the parent 
frustules yet adhering to the sporangium. The comparative striation, 
as measured with a Powell and Lealand spider-line micrometer, is very 
nearly as 4 to 6, and as the individual measurements of the parent 
frustules give for the striation 28 to 30 in ‘001 inch, we have for the 
sporangial ones say about 20 in ‘001 inch. In this gathering there 
are numerous free sporangial frustules wholly formed, and quite as 
coarsely marked, and apparently numerous others of intermediate 
size and striation. Of what value would striation be here? What I 
have said about G. olivacewm is equally true of other diatoms, notably 
of the genus Cymbella. And yet in conjunction with other characters 
the striation should not be ignored. In the same gathering, on 
Isthmia enervis, the striation may be so nearly the same on larger and 
smaller frustules as to appear to be of specific value; but it by no 
means follows that it will be the same in this species from a widely 
different locality, nor does my experience with Eulenstein’s prepara- 
tions of Isthmia enervis coincide with that of Count Castracane. I 
find that the small granules on the connecting zone, or central 
portion, say in ‘001 inch, in the ratio of about 5 to 7, measuring, 


ne 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 249 


however, not with extreme accuracy, yet sufficiently accurately to 
show quite a latitude in this respect. Taking a pretty sure gathering, 
made at the time of the year somewhat remote from the time of the 
conjugation, I am quite prepared to admit that a preparation of the 
so-called Frustulia saxonica, for example, will not show any appre- 
ciable difference in the striation of the frustules; but I would be 
quite unwilling to admit that this diatom could not be obtained from 
another locality considerably more finely or more coarsely marked ; 
indeed, Count Castracane himself admits a difference, though he says 
it has never, to his knowledge, exceeded }, which, as Mr. Kitton shows, 
gives a range in N. crassinervis, if he understands aright, of 27 to 
30 in ‘001 inch! 

“ The general character of the striation, parallel, radiate, &c., the 
character of the median line, if present, the comparative fineness or 
coarseness of the strize—all these are, no doubt, important, as is also, 
within limited range, the number of strie in -001 of aninch. Any one 
looking over Mr. Habirshaw’s ‘Catalogue of the Diatomace’ will 
realize what a frightful increase of species was made by Ehrenberg 
and the earlier observers, from considering the number of rays in 
the genus Actinocyclus as of specific value; equally pernicious is the 
custom too largely indulged in at the present day by many hard- 
working Continental observers, who, looking from the standpoint 
which Count Castracane appears to advocate, find at stated intervals 
new species, founded upon little else than finer or coarser striation, 
or perhaps somewhat different outline. It is, no doubt, quite a com- 
fortable way of working, and of keeping one’s name before the public, 
when one finds what is supposed to be a new diatom, if only knowing 
enough to distinguish the genus, one measures, more or less correctly, 
the length, breadth, or diameter, and the number of striew in -001 of 
an inch, giving sometimes a representation, which if it be one of the 
smaller Navicule, may too often equally well represent many other 
forms, and, finally, to coin some unpronounceable word, or immortalize 
some friend, and send forth the bantling; since nobody can venture 
to question its legitimacy, for does it not differ somewhat from every 
form hitherto figured or described in outline? And has it not a few 
more or less strie in -001 of an inch? I shall be sorry if, in what I 
have said, I am considered as censuring men who are unquestionably 
hard-working and conscientious students of these interesting little 
organisms. I am only regretting that, instead of labouring to reduce 
the genera and species of the Diatomacee, and seeking for broader 
and firmer principles to guide in their study and classification, so 
many worthy persons are contented to accept trivial distinctions as of 
generic and specific value, and they are so encumbering the subject, 
that some day it will be crushed by its own dead weight, giving place 
to a new structure, utilizing as far as possible the ruins, but erected 
upon a more solid foundation.” 

Schmidt’s Atlas of the Diatomacee.*—The recently published 
parts of this work treat of the following genera :—Coscinodiscus, 


* A. Schmidt, ‘ Atlas der Diatomaceenkunde,’ Heft 17 u. 18 (8 pls.) Aschers- 
leben, 1881. 


250 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Craspedodiscus, Auliscus, Pseudoauliscus, Arachnoidiscus, Navicule 
belonging to the groups Didyme and Lyre, Cymbella, &e. 

In Gomphonema Mustela, the author states that the frustules, after 
they have become reduced, by repeated division, to the smallest 
dimensions, leave their pedicel and attach themselves together, in a 
reverse position with respect to one another, by their ventral sides; 
from which he deduces an argument in favour of the animal nature 
of diatoms. 

In the Cymbellez, in which the reproduction of Cymbella gastroides 
and Cocconema Cistula is delineated, the author believes that there is 
also, as in Gomphonema, a distinction between the upper and under 
part of the frustule; and supposes that, when conjugating, they also 
attach themselves to one another in a reverse position. The un- 
symmetrical arrangement of the cell-contents of several species of 
Navicula, already pointed out by Pfitzer, is illustrated by drawings 
of N. dicephala; and the inference is drawn that all species of 
Navicula present a difference between the anterior and posterior ends, 
which is well exhibited in some true Navicule. The very variable 
cell-contents of Cocconema lanceolatum and Cymbella gastroides are 
well illustrated. In Encyonema gracile, the author has detected and 
drawn some very peculiar moniliform corpuscles (possibly parasites) 
with a trembling motion in the middle of the frustules. 


“ Aphaneri ’’—Examination of Water.*—The water of the Lago 
Maggiore, which it has been proposed to convey to Milan, has lately 
been examined by Prof. Maggi by M. Certes’ method,t the samples 
being taken at 65 m. depth, and about 400 m. from the banks. Forty- 
eight hours after a little osmic acid was added, there was obtained a 
small deposit of dead organisms of bacterian form, none of which had 
appeared in the Microscope. He found a solution of chloride of palla- 
dium to have also the effect of hardening these small organisms and so 
making them opaque and microscopically visible. Small irregular 
masses of protoplasmic nature, capable of taking colour from a 
magenta solution, were also thrown down. Prof. Maggi further . 
treated the water of the lake with various colouring agents. Hema- 
toxylin, methyl-violet, magenta, and Lione blue, gave the best results. 
While the same small organisms and protoplasmic masses were mani- 
fested, only the latter, curiously, took the colour. In spring water of 
Valcuvia, and rain-water, microbes like those in the lake, not visible 
with a power of 800 diameters, were revealed by the colouring and 
hardening reagents. 

Prof. Maggi proposes to call these organisms Aphaneri, as dis- 
tinguished from the bacteria and microbes which, without reagents, 
are visible in the Microscope (Phaneri), and among which are agents 
of infection, and which take colour from methyl-violet, magenta, &c. 
The Aphaneri, he thinks, are probably harmless. 


* Nature, xxv. (1882) p. 348. 
t See this Journal, iii. (1880) p. 847, 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 251 


MICROSCOPY. 


a Instruments, Accessories, &c. 


“Acme” Class Microscope.—The “ Acme” Microscope of Messrs. 
Sidle and Co. (described in Vol. IIT. (1880) p. 523) is now adapted 
for being readily converted into a Class Microscope (Fig. 29). This 


is accomplished by removing the metal tripod foot, and substituting 
for it a wooden base of suitable form, carrying upon a jointed arm 
a small lamp. It can then be handed round the class or lecture- 
room. 

We think the ready conversion of ordinary students’ stands into 
class Microscopes, is a point deserving the attention of opticians. 


252, SUMMARY OF CURRENT RESEARCHES RELATING TO 


Browning's Portable Microscope.— This Microscope as set up 
for use is shown in Fig. 80. The stage has the usual rectangular 
motions, and there is also a substage. The speciality of the instru- 


Fig, 30. 


ment is that the body-tube turns on a joint as shown in Fig. 31, and 
that the posterior foot b of the tripod can be closed up between the 
anterior ones. ‘The whole instrument will then pack into a case 


6 x 6 x 9 inches. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 253 


Harting’s Binocular Microscope. — Professor P. Harting has 
suggested * a mode of making a binocular Microscope which has not 
hitherto been described. 

The earliest binocular Microscope was that of Cherubin, 1678,+ who 
simply combined two complete Microscopes in one frame (Fig. 32 {). 
Such a device could obviously only be made available with the lower 


Somes Tomo Momomeme oom ome oo 


powers; with high powers the necessary proximity of the object would 
prevent the possibility of any joint convergence of the two objectives. 

To obviate this difficulty Professor Harting placed two identical 
lenses side by side (A and B, Fig. 33) with their axes at an angle 
mon with one another. If the object ab is at a distance equal to 
twice their focal length, two images of it will then be formed a’ D’ 


* Das Mikroskop, 1859, p. 180. 

+ ‘De visione perfecta, sive de amborum visionis axium concursu in eodem 
objecti puncto.’ Paris, 1678, pp. 77-100. 

¢ This figure has been correctly copied by the engraver, but the eye-pieces in 
A would appear to be too narrow. 


254 SUMMARY OF CURRENT RESEARCHES RELATING TO 


and ab", each of which will be of the same size as the object. 
Two compound Microscopes with eye-pieces C and C’, and objectives 
D and D’, are then used to examine the two images. 

Professor Harting writing in 1858 said “ were the images a’ b’ 
and ab" so clear and sharp that they might be assumed to repre- 
sent the object itself, objectives of short focal length might be used. 
But we are yet far from having the objects so represented by our 
present lenses. Even if the images are formed by objectives of fairly 
low power—l to 2 cm.—the difference between the images and the 


libeh Sst 


object is still too great, as was found as the result of some experi- 
ments made for the purpose. This contrivance cannot therefore be 
applied successfully to the construction of binocular Microscopes, 
which is the more to be regretted as this arrangement seems to 
satisfy better than any other the requirements of true stereoscopic 
vision. Perhaps future improvements in the construction of objec- 
tives will more readily allow of the accomplishment of the desired 
aim.” 

As this was written nearly thirty years ago, it is very probable 
that the defects in the objectives which were then found to mar the 
action of the suggested instrument would not now be met with, but we 
doubt nevertheless if it would be found at all worth while to construct 
such an instrument. Any improvement in the stereoscopic effect over 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. PAB 


that furnished by some of the modern binoculars would be likely 
to be more than balanced by the additional complication of the 
instrument. 


Nachet’s Double-bodied Microscope-tube.*—An ordinary Micro- 
scope can be readily converted into one for two observers by the plan 
shown in Figs. 34 and 35. A nose-piece screws into the end of the 


Fria. 34. 
I i Fria. 35. 


i} 
| 
| 


I 


body-tube, carrying just above the objective a truncated prism, 
which bisects the pencil from the objective, allowing half to pass 
direct to the eye-piece, while the other is diverted by the prism into 
a second tube screwing into the nose-piece and set obliquely. Powers 
of 200 to 300 times can be used. 


Wenham’s Universal Inclining and Rotating Microscope—This 
new Microscope (Plate IV.) has been devised by Mr. Wenham for 
the special purpose of obtaining a large range of effects of oblique 
light both in altitude and azimuth. 

The principal movements are as follows: (1) an inclination of 
the limb together with the body-tube, stage, substage, and mirror, 
in a sector sliding within jaws attached to the rotating base-plate. 
The centre of this inclining motion is (very approximately) the 
point where the plane of the object cuts the optic axis, i.e. a point 
situated about the thickness of an ordinary object-slide above the 
centre of the surface of the stage; (2) a lateral inclination of the 
limb to either side upon an axis attached to the centre of the sector. 
The centre line of this axis prolonged forwards also intersects the 
optic axis in the plane of the object on the stage; (3) a rotation of 


* See Robin, C., ‘ Traité du Microscope,’ &., 1877, pp. 72-3 (2 figs.). 


256 SUMMARY OF CURRENT RESEARCHES RELATING TO 

the instrument upon its circular base, the optic axis being the centre 

of motion. “ - 
The leading principle followed in the construction of the stand is 


. 36. Fig. 37. Yy 
Fic. 36 7 yy, 


that when it is inclined backwards (as in Fig. 36), or turned laterally 
(as in Figs. 37, 38, and 39), or rotated on the base-plate, a pencil of 


Fie. 39. 


light from a fixed source will always reach the object, all the move- 
ments, whether separate or combined, radiating from the object (or 
the prolongation of its axes) as a centre. 

The stage rotates completely and is a modification of Mr. 
Tolles’s, in which the rectangular motions are effected by milled 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 257 


heads acting on the surface and entirely within the circumference.* 
It is mounted on the Zentmayer system, and graduated near the edge, 
“finders” being engraved in convenient positions; two centering 
screws are provided by which exact rotation round the optic axis can 
be secured ; and it can be easily removed, or may be replaced by a 
glass or metal friction-stage, &c. A simple and effective plan has 
been adopted of applying the iris-diaphragm, hemispherical . im- 
mersion illuminator, or Wenham’s “half-disk” illuminator, beneath 
the stage, where they are held by asmall projecting peg and a spring 
latchet. 

The substage can be removed entirely from the lower part of the 
limb by means of a metal dove-tail slide The usual rectangular 
(centering) and rotating motions are provided. 

The substage condenser is furnished with a centering cap and a 
rotating plate of the usual series of slots, central stops, &c., an iris- 
- diaphragm immediately beneath modifies the diameter of the circular 

opening utilized. 

The coarse adjustment is of the usual “ Jackson” form by means 
of a spiral pinion and diagonal rack-work. 

The fine adjustment acts directly upon a vertical slide carrying 
the objective only, and is controlled by vertical milled heads on both 
sides of the nose-piece. 

In illustration of the variety of motions obtained with this Micro- 
scope, Fig. 86 shows the sector inclined at about the usual position 
for working with central illumination; Fig. 87 shows the lateral 
inclination of the limb, &c., the sector being at its highest position ; 
Fig. 38 shows the Zentmayer swinging tail-piece clamped to the 
sector (as suggested by Mr. J. Mayall, jun.), the limb being inclined 
laterally, and the substage removed. ‘This lateral inclination of the 
limb causes the stage to revolve upon a central horizontal axis, so 
as to present the object to the illuminating pencil at all obliquities ; 
Fig. 39 shows the sector at the lowest point so that the microscope- 
body is horizontal, the tail-piece being clamped to the sector, the 
limb swung laterally about 45° (to the right), and the substage re- 
moved. This position of the sector would be that required for 
measuring angles of aperture by means of the graduations on the 
circular base. The axis of the lateral inclining motion is also 
graduated, so that either the degree of inclination of the limb or 
that of the swinging tail-piece can be registered. In all these posi- 
tions, and indeed in every position in which the various movements 
enable it to be placed, the Microscope is very steady. 

The construction of the stand has been carried out by Messrs. 
Ross under Mr. Wenhawm’s instructions, and we understand that they 
purpose making such modifications as will permit a lamp to be 
carried by the swinging tail-piece, or placed at the lower end of the 
sector ; and the mirror to be attached at pleasure to a rotating slide in 
the centre of the base: these additions will add still more to the 
facilities for obtaining obliquely incident light. 

* See the descriptions of similar stages, this Journal, i. (1881) pp. 116-117 
(Figs. 9 and 10), p. 300 (Fig. 46), and pp. 944-6 (Figs. 221-3). 

; Ser. 2,—Vot. II. 8 


258 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Bausch and Lomb Optical Co.’s Trichinoscope.*—Figs. 40 and 
41 show the Trichinoscope recently issued by the Bausch and Lomb 
Optical Co. It consists of two metal plates, each pierced with a central 
hole and hinged together at one end, and so arranged that they can 
be forced together by the screw at the opposite end. Two glass plates 


Fic. 40. 


ll a > 
TTT MATT 


are inserted between them. A simple Microscope can be moved in 
different directions across the apertures in the plates so as to com- 
mand a view of every part. It is focussed by being screwed up and 
down in the socket at the end of the arm which carries it. 


Fra. 41. 


Wt! nT 


A thin slice of flesh having been moistened with a mixture of 
equal parts of acetic acid and glycerine, is put on the lower glass plate 
and spread out by needles or a brush, the second plate is brought 
down upon the lower one and the screw is placed in the slot into which 
it fits. By turning the screw any degree of pressure may be brought to 
bear on the flesh, which may thus be rendered so thin and transparent 
that any trichine present will be readily visible when the Trichino- 
scope is held up between the eye and light. 


““Hampden”’ Portable Simple Microscope.—This instrument 
(Figs. 42 and 43) is made by Messrs. Beck and is the device of the 
wife of a distinguished English statesman now ruling in India. It 
combines, with great portability, very convenient arrangements for the 


* Amer. Jour. Micr., vi. (1881) pp, 183-5 (3 figs.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 259 


most effective use of a dissecting lens or simple Microscope in the 
field or when travelling. 


The lens, stage, and mirror are each carried by a bar sliding on 
the upright stem which screws into the circular foot. The bars can be 


Fic. 43. 


ru li 
———— 


adjusted to any height and secured by the screws, of which the milled 
heads are shown on the right of Fig. 42. When detached the instru- 
$2 


260 SUMMARY OF OURRENT RESEARCHES RELATING TO 


ment packs very conveniently into asmall case 54in. x 23in. x 1} in. 
in the manner shown in Fig. 48, and is then readily carried in the pocket. 

Sir John Lubbock, who has on several botanical excursions taken 
the instrument with him, speaks highly of its usefulness. 


Excluding Extraneous Light from the Microscope.*—In order to 
exclude light of an injurious character, whether falling laterally on the 
eye of the observer or on the stage from above, T. W. Engelmann places 
the Microscope in a dark box, made portable, and admitting the light 
through a funnel-shaped opening in the broad front side. The body 
of the observer as well as the Microscope and its belongings are 
intended to be included in the box, which is 75 em. high, 80 em. 
broad, and 40 cm. deep, and is arranged so as to carry accessory 
apparatus, reagents, coloured glass plates, &c. 


Nachet’s Improved Camera Lucida.—In its original form this 
camera lucida consisted of a rhomboidal prism A B C D, placed 
over the eye-piece of the Microscope, as shown in Fig. 44, and having 

cemented to the face A C a seg- 

Fic. 44. ment of a small glass cylinder H, 

the ray ab from the eye-piece 

and that (a’ b’) from the pencil 
meeting the eye at b. 

The disadvantage of this 
form was that the eye must be 
held very steadily just over the 
glass cylinder E (the function 
of which was to allow the rays 
from the object to pass to the 
eye-piece without refraction), to 
obviate which M. Nachet has 
made use of a suggestion of 
Professor G. Govi, and deposits a thin film of gold on the face 
AC of the prism (Fig. 45). The gold reflects the ray a’ b' to b as 


Fia. 45. Fic. 46. 


before; whilst, at the same time, on account of its translucency, it 
allows the ray a to pass through it from the eye-piece. The small 


* Pfliiger’s Archiy ges. Physiol., xxiii. (1880) p. 571. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 261 


prism E is replaced by a larger one, H’, cemented upon the gold film 
(protecting it also from being rubbed off), and a slight inclination is 
given to the under surface at D’, in order to avoid too great an 
approximation of the pencil to the foot of the Microscope. 

The image of the paper is tinted yellow by the rays reflected from 
the surface of the gold, while that of the object’ is of an emerald 
green tint, that being the colour given to the rays in passing through 
gold. 5 

Fig. 46 shows the camera lucida in place over the eye-piece. 


Abbe’s Camera Lucida.*—Dr. L. Dippel commends the following 
as an extremely simple and complete apparatus for drawing on a 
horizontal surface. 

A small glass cube A (Fig. 47) composed of two right-angled 
prisms cemented together is placed over the eye-piece C, one of the 
prisms having an hypothenuse surface silvered, leaving, however, a 


Fic. 47. 


S =) 


circular hole. The cube is so adjusted that the hole exactly coin- 
cides with the “ eye-point” of a Zeiss No. 2 ocular(C). The mirror 
B is connected with the fastening of A by an arm about 70 mm. from 
the axis of the Microscope. 

In use, the instrument is fastened to the eye-piece cover by two 
centering screws, and the mirror so turned that the surface of the 
table close beside the foot of the Microscope appears to be projected 
on the circular field of the eye-piece. The whole field of view is now 
readily seen, and with uniform sharpness, and this is the case also 
when the higher powers are used, no perceptible loss of light taking 
place in the vision of the microscopical image. One of the most 
essential qualities of a good camera lucida is therefore obtained. 

That the camera is attached to a particular eye-piece, and is not, 
as usual, made adjustable for those of different power, arises from the 
fact that in the higher Huyghenian eye-pieces the eye-point lies too 
near the eye-lens. 


* Bot. Centralbl., ix. (1882) pp. 242-3 (1 fig.). 


262 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Dr. Dippel says that he has thoroughly tested the camera with 
very delicate drawings, and has found it of excellent service, and 
he considers it is to be preferred over all those forms for drawing on 
a horizontal surface in which the microscopical image is seen after 
several reflections, and the pencil direct. 


Curtis’s Camera Lucida Drawing Arrangement.*—Mr. Bulloch’s 
new “Congress” stand has an arrangement for drawing, suggested 
by Dr. L. Curtis, “ which is designed to do away with some of the 
difficulties attending the use of the ordinary camera lucida. A little 
table is fastened to the limb by milled-head screws; paper is placed 
upon this for drawing. One of Hartnack’s right-angled camera 
lucidas is used. Drawing can be done in any position of the 
Microscope. There is hardly more preparation required for this 
than would be required to change an eye-piece. The comfort of this 
arrangement, when one is doing work which requires much drawing 
while observation is going on, needs to be experienced to be 
appreciated.” 


Drawing on Gelatine with the Camera Lucida.t—M. Créteur 
uses a metallic point for drawing objects with a camera lucida, the 
drawing being made not on paper, but on a sheet of gelatine laid on a 
dark ground. The shining point is always visible, and is claimed to 
provide a remedy for the indistinctness of the point of the pencil, which 
is the chief difficulty experienced in drawing with the camera by the 
ordinary method. The drawing can also be readily transferred to 
stone. 

It is questionable whether the advantage gained through the 
greater distinctness of the drawing-point is not more than counter- 
balanced by the disadvantage of not being able to draw on paper. As 
the particular benefit claimed appears to rest upon the shining 
point, that could be obtained without great difficulty with an ordinary 
pencil. 


Iris-Diaphragm for varying the Aperture of Objectives.——In 
1869, Dr. Royston-Pigott applied an Iris-diaphragm behind the 
objective for reducing the aperture of objectives, in support of the 
view which he was then advocating that wide-aperture objectives 
produced confused images. 

The editor of the ‘ Northern Microscopist’ has recently suggested 
the use of such a diaphragm to enable penetration to be obtained 
with wide-angled objectives of different apertures. Fig. 48 is a side 
view of the apparatus, as made by Mr. C. Collins, and Fig. 49 a front 
view. The upper end in the former figure screws into the microscope- 
tube, while the lower receives the objective. The diaphragm is 
opened or shut by sliding the lever projecting at the side. The 
partial closing of the diaphragm does not, of course, contract the 
field, but diminishes its brightness by obstructing the passage of a 
greater or less part of the cone of rays. 


* Amer. Mon. Micr. Journ., iii. (1882) p. 13. 
+ Bull. Acad. R. Méd. Belg., 1880, p. 617. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 263 


In some remarks on the use of the apparatus it is pointed out * 
that it shows the value of wide apertures for good definition, for if a 
preparation of the proboscis of the blow-fly be observed with an inch 
objective having an air angle of 30°, the view is superb, the pseudo- 
tracheal markings come out well-defined and sharp; but close the 
shutter until an angle of 14° or less is obtained, and examine again, 


when it will be found that the definition is not nearly so good, while 
there is more penetration, the whole of the pseudo-tracheal tube being 
observed under one focussing. While in this condition, the eye being 
still applied to the tube, open the shutter to its full extent, and the 
effect of wide aperture will demonstrate itself. 

“‘Perhaps the best object to show the amount of penetration 
possessed by objectives of low angle, may be found in the micro- 
fungus, Myxotrichum deflexum, or M. chartarum, observed under the 
1-inch objective. The former object consists of little patches of grey 
downy balls, from which arise a number of radiating threads, fur- 
nished with a few opposite and deflexed branches. Under an inch 
objective of 30° air angle, but few of these branches can be seen 
under one focussing, the remainder being enveloped in a haze of 
light ; but if a central layer be focussed, the simple closing of the 
shutter will suffice to bring the superior and inferior layers into view, 


though, of course, the image is not so bright and well defined as 
before.” 


Gundlach }-inch Objective t—Dr. L. Curtis recently exhibited to 
the State Microscopical Society of Illinois a new 4-inch objective 
made by Gundlach, and claimed by the maker to have an angle of 
100°. The back lens is large, and extends beyond the border of the 
opening in the screw. This opening, therefore, acts as a diaphragm. 
In order to secure the benefit of the full aperture, the portion of the 
objective can be removed, and an adapter furnished with the Butterfield 
broad gauge screw can be substituted. It has also another screw of 
about the same diameter as the Butterfield screw, but provided with 
a finer thread. The name and description of this screw were not 
known. The front of the objective is ground down to a conical 


* North. Microscopist, ii. (1882) pp. 13-14 (2 figs.). 
+ Science, iii. (1882) pp. 19-20. 


264 SUMMARY OF CURRENT RESEARCHES RELATING TO 


shape. For ordinary use this front is covered with a brass cap, 
having an aperture in the centre to allow the conical end of the 
objective to pass through. The cap can be removed when it is desired 
to use the objective for the examination of opaque objects. On 
removal of the cap the conical sides of the lens are seen to be covered 
with some sort of black varnish to prevent the passage of outside light. 
A Lieberkuhn is furnished, which can be screwed on in place of the 
cap while examining opaque objects. 


Scratching the Front Lenses of Homogeneous-immersion Ob- 
jectives.—It was recently objected to homogeneous-immersion objec- 
tives that the necessity of wiping the oil from the front lens after 
each observation was fatal-to their utility as in time the front surface 
would thus become so scratched as to render the objective unfit for 
use. 

This objection, however, overlooks the fact that even assuming 
it was really impossible to properly clear off the immersion fluid 
without “scratching” the lens, such scratches would not interfere 
with the use of the objectives. As the fluid used for immersion is 
homogeneous, that is, may practically be considered fluid crown glass, 
the scratches are optically obliterated as soon as they are in contact 
with the oil or other medium; in fact, it will be seen on reference to 
the original paper of Mr. Stephenson on homogeneous-immersion 
objectives,* that one advantage of the system was pointed out to be 
that in petrographical work the very imperfect polishing of thin sec- 
tions of minerals, which had previously been a source of difficulty, 
was overcome by the approximately optical identity of the object and 
immersion fluid. 


Fluids for Homogeneous Immersion.{— Dr. H. van Heurck, 
Director of the Antwerp Botanical Gardens, has undertaken an ex- 
tended investigation of fluids suitable for homogeneous immersion, 
which (1) should have an index of 1:510-1-520 (line F), and (2) a 
dispersive power of 0:006 (between D and F), (3) should not be too 
fluid, and (4) should not attack the varnish of the slides. 

Amongst the chemical solutions hitherto suggested, Dr. van 
Heurck mentions Bassett’s fluid (which attacks varnish), chloride of 
cadmium in glycerine, iodide of zinc in glycerine, sulpho-carbolate 
of zinc in glycerine, and distilled chloride of zinc (difficult to use and 
not capable of being well preserved). Of the vegetable substances, 
cedar oil and oil of copaiba are referred to. The first is a product 
not of the cedar, but of Juniperus virginiana, and is much too fluid, and 
attacks the varnish of the cells. The second (distilled from different 
species of Dipterocarpus) is a little less fluid and therefore better. 

To remedy the inconvenience of the extreme fluidity of cedar-oil, 
dammar has been dissolved in it, by which also its index may be raised 
to 1:54. Professor Abbe has recently suggested to the author that an 
excellent fluid may be obtained by dissolving dammar until the index 
is 1-520, and then reducing it to 1°509 by the addition of castor-oil. 


* See this Journal, i. (1878) p. 52. 
t Bull. Soc. Belg. Mier., vii. (1881) pp. xxii,-xxxi. - 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 265 


In his examination of new fluids, Dr. van Heurck met with no 
sufficient success amongst chemical products, but of vegetable sub- 
stances three were discovered which appear to be in every way 
suitable. 

The first is a solution of the resinous gum known as oliban (from 
several species of Boswellia of Hast Africa) partially dissolved in 
cedar-oil. It gives a fairly thick lemon-yellow liquid of refractive 
index 1-510, and dispersive power 0:0077. To prepare the liquid, 
pieces of very pure oliban are powdered finely, and the powder, mixed 
with its own volume of cedar-oil, is heated in the water-bath in a 
glass beaker for 2-3 hours. It is then left till the next day, when the 
supernatant liquid is drawn off. 

The resin (élemi) of Brazil, and the white oily tacamaque of 
Guibourt give equally good solutions with oil of cedar. By dissolving 
the tacamaque in the oil a liquid is obtained with a refractive index 
of 1-519, and dispersive power of -0074. By adding castor-oil to 
the solution in suitable quantity the index is lowered to 1-508, and 
the dispersive power to 0:0072. To prepare the solution, 20 parts 
by weight of the tacamaque are dissolved in the water-bath in 22 parts 
of cedar-oil and 14 parts of castor-oil added. 

According to Professor Abbe, the latter solution and that of 
dammar in cedar-oil constitute the two best fluids for homogeneous- 
immersion objectives. 

The third is copaiba of Maracaibo, derived from Copaifera offici- 
nalis. ‘That found in commerce at Antwerp, and apparently authentic, 
had an index of 1°519, whilst a specimen from Guibourt of copaiba 
of Para was only 1°506. It dissolves readily in cedar-oil. Another 
liquid of 1°510 index and -0076 dispersive power is obtained by dis- 
solving 7 parts of light vaseline in 30 parts of copaiba. A very 
thick liquid results, not attacking varnish even after a contact of 24 
hours. Ifit is found to be too thick it can be diluted by mixing with 
it a solution of copaiba in cedar-oil. 

Other liquids from conifers were tried, but in all the dispersive 
power was found to be too high. 

Dr. van Heurck fears that it will be very difficult to discover any 
substances which will satisfy microscopists who prefer aqueous 
liquids. 


Advantage of Homogeneous Immersion.*—Dr. van Heurck also 
says that “the suggestion of Mr. Stephenson .... constitutes 
certainly the greatest advance which has been made in microscopy 
during late years. Personally we have been able to appreciate, better 
perhaps than any one, the importance of such objectives, for it is 
owing to them that the thousands of drawings in the ‘Synopsis des 
Diatomées de Belgique’ could be furnished in a relatively short time. 
When we think of the trouble that monochromatic illumination has 
caused us, and the frequent interruptions necessitated by the absence 
of the sun, we cannot sufficiently congratulate ourselves upon this 
fortunate discovery, which has enabled us to advance, by a good many 


266 SUMMARY OF CURRENT RESEARCHES RELATING TO 


years perhaps, the publication of our work, all the drawings of which 
have been made or perfected by homogencous-immersion objectives.” 


Vertical Illuminator for examining Histological Elements.*— 
Dr. E. van Ermengem commends the vertical illuminator for the 
illumination of such of the histological elements as can be mounted 
on the cover-glass dry. ‘ Blood-corpuscles present an extraordinary 
appearance, their colour a lively red, their relief very appreciable, 
and the slightest inequalities on their surface clearly visible.” Good 
results had also been obtained in the examination of semen, mucus, 
pus, and liquids containing bacteria, &c.; also of the minute structure 
of muscles and nerve-fibres. 


Griffith's Parabolic Reflector.;—Mr. W. H. Tivy describes a 
method suggested to him by Mr. E. H. Griffith for utilizing a spoon 
for a “ parabolic” reflector. Wind a clean copper wire of =, inch 
diameter closely round the base of an objective three times, twisting 
and bending the ends for a length sufficient to reach a little beyond 
the end of the objective. Cut a section of about half an inch from the 
bowl of a new plated teaspoon, and solder the convex side to the ends 
of the wire, also making the loop solid with solder, and filing it up 
to a good fit and figure, so that it will slip easily on and off the 
objective. The reflector is adjusted by bending the wire. “Thus I 
have a handy and useful piece of apparatus, at the cost of the spoon, 
30 cents.” 

Forrest's Compressorium.—This compressorium (Fig. 50), de- 
signed by Mr. H. E. Forrest, is specially constructed with a view 
to cheapness. It consists of a strong glass (or if desired brass) plate, 


Fic. 50. 


3 inches by 1} inches, with ground edges. A small brass screw 
passes through the plate, the point projecting upwards through it 
about 3 inch. A brass arm, bent so as to form a spring, rotates upon 
the screw as on a pivot, and carries at one end a brass ring holding a 
thin cover-glass, 1 inch in diameter, which covers the centre of the 
plate when in use. A milled nut works upon the screw above the 
arm, and when screwed down brings the cover-glass in contact with 
the glass plate. The spring acts upon and raises the cover, if the 
nut is unscrewed, so that the two glasses can be fixed at any degree 
of proximity required. 

Julien’s Stage Heating Apparatus.{—In a paper on the examina- 
tion of carbon dioxide in the fluid cavities of topaz, Mr. A. A. Julien 
thus describes the method employed in his investigations. 

* Bull. Soc. Belg. Micr., vii. (1881) pp. xxxvii.—xl. 


+ Amer. Mon. Micr. Journ., ti. (1881) p. 238. 
t¢ Journ. Amer. Chem. Soc., iii, (1881) 12 pp. and 4 figs. 


b 
; 
‘ 
a 
2 
é 
ee 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 267 


“The qualitative identification of carbon dioxide in the cavities of 
a mounted thin section of a mineral may be determined, at least with 
probability, after some experience, through various optical appear- 
ances and physical characteristics which have been often described. 
Tt is usually effected with certainty and ease, through the rapid and 
enormous expansion and ultimate disappearance, either of the liquid 
or of the gaseous bubble on the application of a gentle heat for a few 
seconds, such as that of a cigar, the heated end of a rod, or jet of hot 
air, or even a jet of the warm breath conveyed through a flexible 
rubber tube. When the slide and the section are thin, even the heat 
(87° C.) of the tip of one’s finger applied for a few seconds to the 
bottom of the slide, without removal from the stage of the Microscope, 
may be sufficient to produce the characteristic phenomena, e.g. the 
contraction and disappearance of a bubble whose size is relatively 

small to that of the liquid in which it floats. 

For the determination of the temperature of disappearance of the 
bubble, which may vary from 20° to 32° C., several forms of stage 
heating apparatus may be employed (those of Nachet, Beale, Fuess, 
Schultze, Chevalier, Dujardin, Ransom, Polaillon, Ranvier, and 
Vogelsang). In place of all these, a simple and inexpensive apparatus 
may be substituted, consisting of a miniature water-bath, in which are 
immersed the entire section and slide, the bulb of the thermometer, 
and the nose of the objective. It consists of a box of tinned copper 
(Fig. 51) (tinned iron is liable to rust), of length sufficient to project 


a few centimetres on either side of the stage of the Microscope em- 
ployed; the one I use being 23 cm. in length, 4 cm. in width, and 3 em. 
in depth. This is laid across the stage, separated from the metal by 
thin plates of cork cc, and is heated by a short wax taper (night- 
light) underneath either extremity. The slide s may rest upon the 
bottom, guarded from the metal by little rubber bands rr beneath its 
ends, and wedged firmly by a little wooden wedge w beneath the 
horizontal thermometer bulb 6; or a thermometer with a ring-shaped 
bulb may be inserted, upon which the slide may rest directly, firmly 
attached by one or two slender rubber bands. The thermometer 
should be of guaranteed accuracy, with wide degrees, subdivided if 
possible, with a range which need not much exceed 20° to 32° C. 
The preparation is then covered by any pure and clear water, prefer- 
ably filtered (distilled is unnecessary), to a depth of about 2cm. A 
circular aperture in the bottom of the box, 18 mm. in diameter, is 
covered with glass attached by cement, and through this the light is 
thrown up from the mirror. The cavity to be examined is then care- 


268 SUMMARY OF CURRENT RESEARCHES RELATING TO 


fully adjusted and focussed, a taper is lit, and the eye remains at the 
eye-piece until the critical point is reached. The glass tube ¢, with 
its point terminating just below the edge of the slide, is connected 
with the mouth during the experiment by a small rubber tube. As 
the temperature slowly rises, a constant current of small bubbles of 
the warm breath (whose temperature, 32°, only assists the operation) 
may be blown with little fatigue through the tube, to effect a thorough 
intermixture of unequally heated layers in the water stratum. The 
determination of the temperature of disappearance of the bubble is 
easily obtained within five minutes, and that of its reappearance in 
about the same time. A low-power objective may be carefully wiped 
if its anterior lens is dimmed by flying drops or rising vapour, when a 
high temperature is being attained ; but it is best to insert the whole 
objective in a small, narrow glass beaker floating upon the surface of 
the bath over the preparation. 

The apparatus, as thus constructed, may, the author thinks, be 
found the most convenient warm stage when high temperatures are 
required ; but another still more simple, lately devised, will best serve 
for the determination of carbon dioxide, and consists of the following 
parts :— 

First, a shallow glass tank (Fig. 52), with thin and well-annealed 
sides, of size sufficient to enclose the slide, upon which the thin 


Fig. 52. 


section is mounted. For this purpose I use a small chemical beaker 
B, with the thinnest bottom, and with its upper portion cut off, forming 
a thin round glass tank, about 6 cm. in diameter, and 8 cm. deep. 

Secondly, a plate of copper or brass, like that used in Schultze’s 
apparatus, or more simply one of the form represented in the figure d e. 
Its dimensions, proportioned to those of the beaker-tank and of the 
stage of a large Microscope, are as follows:—Length, 23 cm.; 
diameter at centre, 6°5 cm.; width of arms, 3:5 cm.; central aperture, 
2°5cm.; height of wire support, 13 cm.; thickness of plate, 1 mm. 
Each arm is wrapped in pasteboard, to prevent radiation, to the extent 
indicated by the shaded portion. 

Thirdly, a delicate thermometer, with a small, short bulb bent at 
right angles to the stem, and a very fine column, to obtain sufficient 
sensitiveness to minute variations of temperature, and complete 
immersion of the bulb in the small volume of liquid employed in the 
bath. The scale need not exceed in range from about 20° to 82° C., 
the thermometer being of such length that when in position the scale 
from 27° to 30° C. may be on the level of the eye-piece of the Micro- 


ZOOLOGY AND BOTANY, MIOROSCOPY, ETC. 269 


scope, and readily visible without motion of the head. Each degree 
of the column should be about a cm. in length, and subdivided to 
tenths. 

Lastly, a pointed glass tube, with flexible rubber connection for 
blowing, and a wire supports, to receive both this and the thermo- 
meter, attached to the metal plate. 

. The latter is laid upon the stage of the Microscope, separated by 
thin plates of cork or a perforated piece of pasteboard; the tank, 
supplied with about 40 cc. of water, is placed over the central aper- 
ture a, and a taper beneath an extremity of one arm of the plate, and 
the apparatus is then ready for use in the way already described, the 
water of the tank being heated by conduction through the metal plate. 
‘The section of the mineral is best mounted upon a very thin slide, 
45 mm. by 26 mm., and this is guarded as before with rubber bands, 
and held down by one or two little brass weights. Only a single 
' taper is necessary for the low temperature required in the examination 
of carbon dioxide cavities, and even with this a temperature of 43° C. 
may be obtained in the bath within a few minutes. The disappearance 
of the bubble may be completed in less than five minutes, the taper 
being removed as soon as the rising column approaches within 2 or 3 
degrees of the critical point, roughly determined by a previous trial. 
If two tapers are used, the temperature of the water may be raised to 
55° in about 20 minutes, or even much higher, by the use of Bunsen 
gas burners. In summer the temperature of the atmosphere alone 
may be sufficient, especially if assisted merely by the current of warm 
breath, to obliterate the gas bubble. Its return may be readily caused, 
in a warm atmosphere, by adding from time to time a few drops of 
cool water to the bath, while the eye remains at the eye-piece, and a 
steady current of air is blown through the glass tube. Mounted 
slides used for such experiments must be labelled by writing with a 
diamond, or the paper label may be rendered waterproof by being 
coated successively with weak size and any transparent varnish, such 
as copal or shellac. 

From these experiments it may be inferred that with this appa- 
ratus, which may be called the immersion warm bath, it matters little 
for most purposes what liquid, stand, or objective is employed; that 
water is preferable to glycerine, from its greater mobility, convenience, 
and lack of cost; that its bulk is immaterial, so long as the bulb of 
the thermometer is covered; that it is decidedly advantageous to 
immerse the anterior lens of every objective in the bath, to avoid the 
annoying interference with observation produced by the vibration of 
the surface, and by the necessity for repeated refocussing, when the 
objective is above the surface of the liquid ; that careful determination 
on minute cavities, with high powers, carried on slowly to enable the 
preparation, objective, and thermometer to assume the same tempera- 
ture, may be as accurate as any others; and that there is no difficulty 
in obtaining satisfactorily the two determinations within ten minutes 
to an approximation of about one-twentieth of a degree. 

The descriptions of this method, and of these forms of apparatus, 
have been given in the more detail, inasmuch as they may be of 


270 SUMMARY OF CURRENT RESEARCHES RELATING TO 


service in many other branches of thermal microscopy where the exact 
determination of the temperature applied is desirable, e. g. as sug- 
gested by Mr. A. H. Elliott, in the determination of the melting point 
of rare chemical substances, &c. For this purpose, the apparatus in 
Fig. 51 might be supplied with another tube, on the opposite side to 
those represented, through which might be inserted, beneath the 
objective, a small glass tube containing the substance to be examined, 
and thus immersed, by the side of the thermometer bulb, in the water, 


oil, paraffin, or other liquid which the circumstances may require for 
the bath.” 


Beck’s Achromatic Condenser for Dry and Immersion Objectives. 
—In an earlier form of (dry) condenser (Fig. 53), Mr. Beck made 
use of a revolving front rotating a series of lenses mounted on a plane 


Fig. 53. Fig. 54. 


surface over the back combination. This plan was, however, only 
available for a dry condenser ; if used for immersion, the connecting 
fluid would be drawn away by capillary attraction. 

To avoid this inconvenience, the new form shown in Fig. 54 has 
been devised, the movable series of front lenses being mounted 
in a segment of a sphere and rotated by a milled head acting on a 
pinion and toothed disk. The first lens, when brought over the back 
combination, has a low angle, and is intended for use without fluid for 
histological objects. By revolving the diaphragm, the angle can be 
varied from 85° to 7°. The next is a full aperture lens with which, 
by revolving the diaphragm, the angle can be varied from 180° down- 
wards. The third lens, with full aperture of diaphragm, has an 
angle of 110° in glass = 1°25 N.A., and is truncated, cutting out the 
central rays. The fourth lens has also an aperture of 1°25, and is 
truncated, so as to stop out all rays up to 180° inair. The fifth is 
similar to No. 3, but the periphery is painted over, so as to allow 
pencils only at right angles to pass. 


Pennock’s Oblique Diaphragm.*—Mr. E. Pennock suggests an 
adaptation of Mr. Mayall’s spiral diaphragm,f to be attached to the 


* Amer. Journ. Micr., vii. (1881) p. 161 (8 figs.). 
+ See this Journal, i. (1881) p. 126. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. DA 


under side of the stage, for shutting off all light except a small pencil 
from the mirror. It may be mounted in either of two forms: the one 
to fit into the usual tube, which, 

in the cheaper Microscopes, is Fie. 55, 

attached to the under side of the 
stage, the other to screw directly 
into the stage aperture. 

The device is shown in Fig. 55. 
The milled edge serves to rotate the 
plate with the spiral slot over the 
radial slot (shown by dotted lines), 
thus giving varying degrees of 
obliquity. 

Stereoscopic Vision with Non-stereoscopic Binocular Arrange- 

-ments.—It will be remembered that in his paper “ On the Conditions 

of Orthoscopic and Pseudoscopic Effects in the Binocular Micro- 
scope,’ * Professor Abbe pointed out that an orthoscopic (stereo- 
scopic) effect was produced if the inner halves of the “ Ramsden 
circles” just above the eye-pieces were shut off by diaphragms (that 
is like O, Fig. 56), and a pseudoscopic effect when the outer halves 
were so dealt with (that is like P, Fig. 57). 


Fic. 56. Fic. 57. 
0 P 


Dr. A. C. Mercer, of Syracuse, U.S.A., points out that this explan- 
ation solves a difficulty which has perplexed many microscopists, and 
has hitherto remained unexplained. Powell and Lealand’s high- 
power binocular is essentially non-stereoscopic, and theoretically ought 
not to give any appearance of relief to the objects. It has nevertheless 
been frequently observed that a distinctly stereo- 
scopic effect was obtained, and this was attributed Fic. 58. 
entirely to the imagination of the observer. Dr. 
Mercer, however, shows that it is a true and not an 
illusory effect, and that it depends upon the extent 
to which the eye-pieces are separated. 

When the eye-pieces are at such a distance apart 
that the Ramsden circles correspond exactly with 
the pupils of the eyes, centre to centre (Fig. 58), the 
object appears flat. If, however, they are racked 
down so as to be somewhat nearer together, the 
centres of the pupils fall upon the outer halves of 
the Ramsden circles, and we have the conditions 
for orthoscopic effect; while if they are racked © 
up so as to be more separated the centres of the pupils fall on the 
inner halves and we have pseudoscopic effect. 

This is quite in accordance with what takes place in the use of 


* See this Journal, i. (1881) pp. 203-11 (3 figs.). 


* 


Y 
ZY 


i) 


272 SUMMARY OF CURRENT RESEARCHES RELATING TO 


eye-pieces, the halves of which are actually covered with diaphragms, 
for when the inner halves are cut off the tubes naturally require to be 
racked down to diminish the separation of the eye-pieces, and in the 
converse case to be racked up; Dr. Mercer also satisfied himself by 
experiment as to the validity of his deductions by observing sugar 
pills pushed half-way through holes in black cards, the pills being 
marked with cross marks in pencil to increase the effect. They could 
be made to appear convex, concaye, or flat, according to the position 
of separation of the draw-tubes. 

We have, for simplicity, referred to the covering up of both halves 
of the eye-pieces, but it is not of course necessary to cover up more 
than one.* 

In order to obtain the best stereoscopic effect the halves (or one 
of the halves) of the eye-pieces of the Powell and Lealand or other 
similar binocular arrangements should be actually shaded by dia- 
phragms so as to aid in properly centering the pupils, but Dr. Mercer’s 
object is to show that the effects observed with ordinary eye-pieces 
are explicable upon proper theoretical principles, and so to relieve 
those observers who have insisted upon the existence of true ortho- 
scopic effects in such cases, from the reproach which has un- 
justifiably attached to them on account of their supposed abnormal 
and unscientific development of a power of drawing upon their 
imagination. 


[The Bibliography for the period intervening between that contained in the 
Journal of October 1880 and the end of 1881, will be found in the Appendix to 
the next volume. ] 

Axsse’s Experiments on the Diffraction Theory of Microscopical Vision. 

[General Remarks. ] 
Journ, of Sci., TV. (1882) pp. 118-9. 

Acme Microscopes. Amer. Natural., XVI. (1882) p. 261. 

American Society of Microscopists. 

[Review of Proceedings for 1881, and remarks on the meeting at Elmira 
for 1882.] 
The Microscope, I. (1882) pp. 175-7. 

Angular Aperture. 

[Letter by ‘ Akakia,’ describing Dr, Robinson’s method of measurement. | 
Engl. Mech., XXXIV. (1882) pp. 454-5. 

Browne.t, J. T.—A much-needed stop. 

[Suggestion for a “ thumb-screw ” to prevent Microscopes at Soirées being 
focussed too low to the injury of tlie slides.] 
Amer. Mon, Micr. Journ., III. (1882) p. 39. 

Bvtiocu’s New “ Congress” Stand. 

Amer. Mon, Micr, Journ., III. (1882) pp. 9-13 (2 figs.). 

Carlisle Microscopical Society—Inaugural Address by the President, Canon 
Carr. North, Microscopist, 11. (1882) pp. 17-19. 

Carr, E.—Scee Carlisle. 

Cheap Microscopes. 

{Letter by C., advocating the encouragement of their purchase and 
display, and further discussion by Welborn, G., Ollard, J, A., Cooper, 
C. C., F.; J., E. Holmes, A., E. C., and Medehanstade.] 

Eng!. Mech., XXXIV. (1882) pp. 470, 495-6, 520-1, 545. 

Cox, J. D.—Prof. Rogers’ Micrometers. 

Amer, Mon. Micr, Journ., IIL. (1882) pp. 23-5. 


* See this Journal, i. (1881) p. 211, Fig. 38. 


1 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 273 


Crisp, F.—Notes sur l’Ouverture, la vision microscopique et la valeur des 
objectifs 4 immersion a grand angle. (Notes on Aperture, Microscopical Vision, 
and the value of wide-angled Immersion Objectives)—contd. 

{ Transl. of paper I. (1881) pp. 303-60.) 

Journ. de Microgr., V1. (1882) pp. 44-8, 91-5 (13 figs.). 

Curtis, L.—New 3-in. Gundlach Objective of 100°. 

Amer, Mon, Micr. Journ., IIL. (1882) pp. 19-20. 
The Microscope, 1. (1882) pp. 194-5. Science, III. (1882) pp. 19-20. 
Davis, G. E.—The limiting Diaphragm or Aperture Shutter. 
North. Microscopist, 11. (1882) pp. 13-14 (2 figs.) p. 75. 
Amer. Mon. Micr. Journ., U1. (1882) pp. 49-50. 
Engl. Mech., XX XY. (1882) p. 25 (2 figs.). 
3 a A Visit to an Objective Factory. 

[W. Wray’s, Highgate. } 

North. Microscopist, 11. (1882) pp. 21-4. 

Drieret, L.—Abbe’s Camera Lucida. 

Bot. Centralbl., TX. (1882) pp. 242-3 (1 fig.). 

Forrest’s (H. E.) Compressorium. North. Microscopist, Lf. (1882) p. 51. 

GrirritH, E. H.—The Griffith Cell. Amer. Mon. Mier. Journ., U1. (1882) p. 9. 

GuILLemIn, A.—Le Monde Physique. Tome Il. La Lumiere. (The Physical 
World, Vol. I, Light.) 

[Contains a Chapter on the Microscope (20 pp., 20 figs., and 3 coloured 
Plates), 2 section on Microscopical Photography (7 pp. and 5 figs.), and 
one on the Applications of Photography to the Arts and Physical and 
Natural Sciences, 4 pp. and 3 figs.] 

8vo, Paris, 1882. 668 pp., 353 figs., and 26 plates. 

Hrrcucock, R.—Large and Small Microscopes. 

[Rejoinder to C. Stodder.] 

Amer. Mon. Wicr. Journ., U1. (1882) pp. 16-7. 
be 5, The Microscopist. 

{Further reply as to Stowell’s ‘ The Microscope.’] 

Amer. Mon. Mier. Journ., I11. (1882) pp. 18-9. 

Homes, E.—Drawing, &c., from the Microscope. 

[Recommends Mr, Dallinger’s plan of drawing on finely smoothed 
glass. | 

Sci.-Gossip, 1882, p. 39. 

Journal of the Royal Microscopical Society for 1881. 

[Note on the small number of original contributions to the ‘ Transactions’ 
and the reason for it.] 

Journ. of Sci., [V. (1882) p. 56. 

Microscopical Societies. 

[Note as to an intended alteration in the printing of their Reports.] 

Amer. Mon. Micr. Journ., U1. (1882) pp. 14-5. 

Mus, J. L. W.—Dark-field Illumination by the Bull’s-eye Condenser. 

[Placed beneath the stage, plane side uppermost, with a spot of black 
paper in the centre. ] 

North. Microscopist, 11. (1882) p. 39. 
5 * Substitute for a Revolving Table. 

[A piece of table oil-cloth, 15 in. sq., the cloth side turned to polished and 
the oil side to painted tables. ] 

North. Microscopist, 11. (1882) pp. 39-40. 

Nacuet, C. §., Death of. Journ. de Microgr., V1. (1882) pp. 3-4. 

Objectives, Verification Department for. 

{Tabular results of measurements of objectives. ] 

North. Microscopist, IL. (1882) pp. 7, 24, 59. 

OLLarD, J. A.—Mr. Kitton’s Illumination. 

[Commending same, and recommending the use of distilled filtered water, 
filling the globe full to prevent a shaky light, and not using too much 
sulphur chlorate (first filtered). ] 

Sci.-Gossip, 1882, p. 47. 


Pockiinctoy, H.—The Microscope at Home. 
Engl. Mech., XXXIV. (1882) pp. 538-9, 560-1. 
T 


Ser. 2.—Vot. II. 


274 SUMMARY OF CURRENT RESEARCHES RELATING TO 


PrRinGsHEIM’s Photochemical Microscope. 
Quart. Journ. Micr, Sci., XXII. (1882) p. 86. 
S., H. C.—An “ English Mechanic ” Microscopie Club. 
Engl. Mech., XXX1V. (1882) p. 615. 
Saut’s and Swirt-Brown Microscopes. 
Engl. Mech., XXXIV. (1882) p. 463 (3 figs.). 
Scuroper, H.—Ueber Projektions-Mikroskope. (On Projection Microscopes.) 
Centr. Zig. f. Optik u. Mech., UII. (1882) pp. 2-4, 15-17 (1 fig.). 
Surerersotrom, W.—Improvements in Photo-micrography. 
North. Microscopist, 11. (1882) pp. 48-9 (2 figs.) p. 75. 
Fe » Use of the ‘ Aperture-shutter’ in Photo-micrography. 
North. Microscopist, II. (1882) p. 75. 
Slow motion for Micro. Stand. 

[Letter by ‘Sunlight,’ describing the ordinary form used with the 

‘ Jackson Model.’ | 
Engl, Mech., XXXIV. (1882) p. 457 (1 fig.). 
Srattyprass, H. M.—Microscopic Illumination. 

[Approval of F. Kitton’s Hollow Glass Sphere Method, I. (1881) pp. 112-3 
—by adding a few drops of pure sulphuric acid, cloudiness of the liquid 
is prevented. | 

Sci.-Gossip, 1882, p. 64. 
Stopper, C.—Large vs. Small Stands. 

{Reply to R. Hitchcock’s Criticism. ] 

Amer. Mon. Micr. Journ,, III. (1882) pp. 13-4. 
SurroLk, W. T.—On Microscopical Drawing. Sci.- Gossip, 1882, pp. 49-50. 
TISSANDIER.—Microscopie Photography in Paris. 

(Abstr. of article from ‘ La Nature.’ ] 

Engl. Mech,, XXXIV. (1882) p. 561. 


p. Collecting, Mounting and Examining Objects, &c. 


Injection of Invertebrate Animals,*—G. Joseph uses filtered 
white of egg, diluted with 1 to 5 per cent. of carmine solution, for 
cold injections. This mass remains liquid when cold; it coagulates 
when immersed in dilute nitric, chromic or osmie acids, remains 
transparent, and is sufficiently indifferent to reagents. A mass of 
similar properties is made of glue liquid when cold, coloured with 
the violet extract of logwood reduced with alum. Injection is effected 
in the case of worms (leech and earthworm), by way of the ventral 
or dorsal vessel, with large Crustacea by the heart or the ventral 
vessel which lies in the sternal canal. 

In many cases, especially when lacunar spaces have to be filled, 
useful preparations are obtained by natural injection (auto-injec- 
tion, or autoplerosia), Natural injection of Meduse is effected 
without injuring the vessels; in the case of Crustacea, Insects, and 
Mollusca, through a slit with an opening at the side remote from it. 
Medusze are laid in a glass vessel, with the bell downwards, and a 
bell-jar ending in a narrow tube above is placed over it and made 
air-tight; after the Medusa is covered with the injection-mass, the 
air in the glass is exhausted, and the sea-water running out by slits 
in the lower side of the annular canal the coloured fluid runs in. 


* Ber. naturw. sect. Schles. Ges., 1879, pp. 36-40, Cf. Zool. Jahresber. Neapel 
for 1880, i. pp. 45-6, 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 275 


In the case of leeches and large species of earthworms, the natural 
injection is made from the ventral sinus. In all cases a glass tube is 
used, with a finely drawn-out point. The injection is complete when 
the injection issues from the counter-opening. 

Animals to be injected alive are kept quiet by cold (laying upon 
ice). Besides the animals mentioned, large caterpillars, beetles, 
Libellulid larvee, locusts, &c., have served as objects for injection ; 
the glass cannula is introduced into the posterior end of the dorsal 
vessel, and the counter-opening is made in the ventral vessel, and 
vice versa. 


Cold Injection Mass.*—A. Wikszemski describes a modification of 
Pansch’s method:—Thirty parts by weight of flour and one of ver- 
milion are mixed while dry, and then added to 15 parts by weight of 
glycerine and subjected to a continuous stirring until of a homogeneous 
viscous consistency ; then 2 parts of carbolic acid (dissolved in a little 
spirit) are added to it, and finally 30 to 40 parts of water. This injec- 
tion mass is specially adapted for subjects already injected with carbolic 
acid (in the proportion of 15 part by weight each of carbolic acid, 
spirit, and glycerine to 20 of water); 24 honrs are allowed to elapse 
between the two injections. It is a good thing to introduce a little 
dilute injection first. 


Staining with Saffranin.;j—According to W. Pfitzner, staining 
with saffranin is most successful with chromic acid preparations which 
have been entirely freed from the acid, less so with substances 
hardened in picric acid; the only tissues suited to it are those which 
very readily take up colour, and these must be cut extremely thin. 
The sections are transferred to the staining fluid (1 part saffranin, 100 
absolute alcohol, 200 distilled water) from distilled water, are again 
placed in distilled water after a few seconds, and then into absolute 
alcohol, from which they are removed at the right moment (i.e. when 
the nuclei are properly stained) to dammar varnish. The advantage 
of staining with saffranin is that it affects the nucleiexclusively. Dr. 
M. Flescht remarks that the advantage claimed by Pfitzner for 
saffranin has been shown by Hermann to be shared with it by other 
aniline dyes when applied in the same manner. 


Staining with Silver Nitrate—Staining with nitrate of silver is 
very difficult to effect in the case of marine organisms, owing to the 
abundance in which chlorides occur inthem. R. Hertwig § meets this 
difficulty by washing the animals (after hardening in osmic acid) with 
distilled water until the water used for washing gives but a very 
slight precipitate with solution of silver nitrate, and then allowing a 
1 per cent. solution of the nitrate to act for 6 minutes. 


* Arch. f. Anat. u. Entwick., 1880, pp. 232-4. 
+ Morph. Jahrbuch, vi. (1880) p. 469. Cf: Zool. Jahresber. Neapel for 1880, 
i. p. 43. 
$ Ibid., pp. 43-4. 
§ Jen. Zeitschr., xiv. (1880) p. 324. 
we 2 


276 SUMMARY OF CURRENT RESEARCHES RELATING TO 


C. Golgi,* in studying the peripheral and central nervous fibres 
of the spinal cord, exposes the nerves to the action of osmie acid, 
chromic salts, and silver nitrate, according to certain methods of 
combination. For example, a nerve is removed with care from a 
freshly killed animal (rabbit), and placed in a mixture of 10 parts of 
a 2 per cent. solution of potassium bichromate with 2 parts of 1 per 
cent. osmic acid solution. After about an hour the nerve is divided 
into smuller pieces of 3 to 1 cm. in length, and again placed in the 
solution, where it is left some hours longer (it must be examined every 
8 hours), and finally is placed for not less than 8 hours in 0°5 per 
cent. solution of nitrate of silver, and then mounted in dammar 
varnish in the ordinary way. Better preparations are produced by 
placing nerves which have been exposed—in the case of peripheral 
nerves 8 hours, of central nerves 10 to 15 days—to the action of 
bichromate of potash, then from 12 to 24 hours to silver nitrate, and 
mounted in dammar varnish without previous exposure to the light. 


Staining Tissues treated with Osmic Acid.—Damaschino, in a 
communication f to the Société de Biologie, advocates osmic acid in 
the form of a solution of 1 per cent. for human spinal cord divided 
into lengths of 1 cm., and for the spinal cord of smaller animals 
treated entire ; he afterwards hardens in absolute alcohol. If it is 
then not sufficiently hard, the preparation is saturated with gum before 
being placed in the alcohol; the sections, which are penetrated with 
gum, are transferred unstained to Canada balsam without being pre- 
viously freed of gum by means of water. 

Referring to this communication (which contains no really new 
point), L. Malassez { remarks on the difficulty of staining substances 
which have been treated with osmic acid, and for this reason he first 
stains the sections with other staining matters, and then exposes them 
to the action of osmic acid, and this in such a way as to allow only 
the vapour of the solution of acid to act. He claims to have obtained 
admirable results by this method, since in this way all the properties 
of the osmic acid come into play without affecting the other staining 
substances. 

R. Hertwig § placed the animals (Ctenophora) examined by him 
in a 0°05 per cent. solution of osmic acid, to which in some cases 
he added acetic acid solution of 0°2 per cent. for from 5 to 15 minutes, 
according as he wished to investigate the epithelium or the elements 
of the gelatinous tissue; he then stained with carmine and finally 
preserved in dilute glycerine. 


Mounting the “Saw” of the Tenthredinide.||—-Mr. P. Cameron 
describes his method of mounting and preserving the “saw” of the 
Tenthredinide for microscopical examination, a method which can be 
applied to microscopical mounting generally. 


* Arch. per le Sci. Med., iv. (1880) pp. 221-46 (1 pl.). Cf. Zool. Jahresber. 
Neapel for 1880, i. p. 44. 

+ Gazette medic. Ann., li. (1880) p. 636. { Ibid., p. 637. 

§ Jenaisch. Zeitschr., xiv. (1880) p. 315. Cf. Zool. Jahresber. Neapel for 
1880, i. p. 41. 

|| Trans. Entomol. Soc. Lond. 1881, pp. 576-7. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 277 


With fresh specimens the saws can be extracted by pressing the 
abdomen, when they will be protruded and readily extracted. With 
old specimens it can be done equally well by placing the insect in a 
relaxing-dish, or, more promptly, by steeping it in water for a day, 
when they can be taken out in the same way as with fresh insects, 
the only difficulty being experienced with insects full of eggs. For 
their better examination the four pieces composing the ovipositor 
proper should be separated ; after which they must be steeped in 
turpentine for a day or two so as to get rid of air. This is be~t done 
by enclosing them in a small folded piece of paper; and, if they be 
properly labelled, many different preparations can be placed in the 
turpentine-bottle together. 

Next take a sheet of fine Bristol board, and cut it up into pieces, 
say 12 lines x 9 lines, and punch at one end a round or square hole, 
four or five lines across. On the lower side of this fasten, by means 
of Canada balsam dissolved in benzine, a cover-glass. When this 
has dried fill up half the cell thus formed with the same composition, 
spreading it as evenly as possible, and in it arrange your preparation. 
Put it aside for some hours in a place where no dust will fall on it, 
then fill the cell with enough balsam to run over the edge of the cell, 
place a cover-glass over it, and press it down. Ali that now requires 
to be done is to allow the preparation to dry, taking special care to 
keep it flat, to label it, and stick a pin through the card, by means of 
which it is fixed in the cabinet alongside the insect from which the 
part was taken. To examine it under the Microscope, all that is 
necessary to do is to place an ordinary glass slide across the stage, 
and put the card on it, in doing which it is not necessary to take 
the pin out of it if a short pin be used. 

The great advantage of this plan for entomological purposes is 
that it does not necessitate the formation of two distinct collections, 
which must be the case if dissections are mounted on glass slides, 
which cannot of course be placed alongside the insects. Besides that, 
it is cheaper, more expeditious, and safer ; for the cards are so light 
that no injury comes to them from falling, or getting loose in the box. 
If desired, a coloured ring can be put round the top object-glass by 
the turntable in the ordinary way, but except for ornament, is not 
necessary. ‘The author usually prepares two or three dozen of the 
cards with one cover-glass on at a time, so as to have them ready for 
use. The object of letting the dissections harden in the cell, half 
filled with balsam, is that three or four separate parts may be 
arranged in the most suitable way in the same cell without fear of 
their being disarranged or injured when the top cover-glass is put on, 
while both might happen if the whole operation was performed at once. 

For the examination of the saws, a quarter-inch objective is 
the best, the teeth, in some cases, are so fine that they are apt to be 
overlooked if lower powers are used. 


Mounting Butterfly-scales.*—Dr. D. H. Briggs recommends the 
following process. Dissolve 1 part of Anthony’s “ French Diamond 


* Amer. Mon. Mier. Journ., ii. (1881)_p. 227. 


278 SUMMARY OF CURRENT RESEARCHES RELATING TO 


varnish” in 2 parts of pure benzole. Apply a drop or two of the 
solution to a slide, and in a few seconds, or as soon as the varnish has 
set, press the wing of the butterfly gently upon the slide, and then 
carefully lift it away. The scales will be found transferred to the 
slide in their beautiful natural arrangement * on the wing. Make a 
shallow cell around the mounting and apply the cover-glass. Canada 
balsam must not be used, as it disarranges the object. 


Imbedding Ctenophora.t—For imbedding Ctenophora (for the 
most part after hardening in osmic acid), R. Hertwig employs gum- 
glycerine very largely diluted with water ; it is allowed to remain in 
contact with the air, with the substance to be cut immersed in it, 
until it has acquired the consistency of a stiff syrup. Shrinkage of 
the gelatinous tissue is to some extent obviated by this plan, owing 
to the slowness with which it absorbs the constantly thickening gum- 
glycerine. 


Staining Living Protoplasm with Bismarck Brown.i—L. F. 
Henneguy having treated Paramecium aurelia with an aqueous solution 
of aniline brown (known in commerce as “ Bismarck brown”), was 
surprised to see them assume a rather intense yellow brown colour, 
and move rapidly about in the fluid. The colour first appeared in 
the vacuoles of the protoplasm, and then it invaded the protoplasm 
itself. The nucleus generally remains colourless, and thus becomes more 
visible than in the normal state. Infusoria thus coloured were kept 
for nearly fifteen days. If a yellow-tinted Paramecium is wounded 
or compressed so as to cause a small quantity of the protoplasm to 
exude, it is seen that it is really the protoplasmic substance which is 
coloured. All Infusoria may be equally stained with Bismarck brown, 
but no other aniline colours employed by the author exhibited the 
same property, they only stained the Infusoria after death, and some 
of them are in fact poisonous. 

As it is generally admitted that living protoplasm does not absorb 
colouring matters, and that Infusoria are essentially composed of 
protoplasm, -M. Henneguy endeavoured to ascertain whether proto- 
plasm in general, of animal or vegetable origin, behaved in the same 
way in the presence of aniline brown. 

A tolerably strong dose of Bismarck brown was injected under the 
skin of the back of several frogs. After some hours, the tissues were 
uniformly tinted a deep yellow, the muscular substance especially 
had a very marked yellow tint. ‘The frogs did not appear in the 
least incommoded, 

Small fry of trout placed in a solution stained rapidly and con- 
tinued to swim about. 

Finally, a guinea pig, under whose skin some powder of Bismarck 
brown had been introduced, soon presented a yellow staining of the 
buccal and anal mucous membranes and of the skin. 

Seeds of cress sown on cotton soaked with a concentrated solution 

* It should be observed that the scales will have their under sides uppermost, 
which is not the “ natural arrangement.”—Eb. 


+ Jen. Zeitschr., xiv. (1880) pp. 313-14. 
¢ Rey. Internat. Sci. Biol., viii. (1881) pp. 71-2. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 279 


of the Bismarck brown sprouted, and the young plants were strongly 
stained brown ; but on crushing the tissues and examining them under 
the Microscope it was ascertained that the protoplasm of the cells 
was very feebly coloured; the vessels on the contrary showed a very 
deep brown staining up to their termination in the leaves. 

The mycelium of a mould which had been developed in a solution 
of Bismarck brown, was clearly stained after having been washed 
in water, whilst it is known that the mycelium which frequently 
forms in coloured solutions, picrocarmine, hematoxylin, &c., remains 
perfectly colourless. 

Other aniline colours injected under the skin of frogs stained the 
fundamental substance of the connective tissue as deeply as did the 
Bismarck brown; but the cells of the muscular substance remained 
perfectly colourless. 

The author concludes therefore that Bismarck brown possesses 
the property of colouring living protoplasm both in plants and 
animals. 


Preservation of Infusoria and other Microscopical Organisms.* 
_—A. Certes, in a note supplementary to his previous communications,f 
says that five years’ experience has only confirmed his view of the 
efficacy of osmic acid and iodized serum for preparing Infusoria ; but 
sometimes, notwithstanding precautions, the animalcules become black 
and opaque from a too prolonged action of the osmic acid; or, 
especially when iodized serum or lemon juice has been employed as 
a fixing reagent, mouldiness attacks the preparations either because 
the bottles have been badly corked or precautions for excluding germs 
from the preparations have been neglected. 

It will be found however that ammonia (3) will clear prepara- 
tions blackened by osmic acid, and thus the always dangerous use of 
cyanide of potassium will be avoided ; but it is necessary to watch the 
operation with care, the time of immersion in ammonia being 
essentially variable according to the thickness of the animalcules and 
the quantity of osmic acid in excess. 

With regard to mouldiness, it is possible, with certain precautions, 
to filter the liquid which holds the altered gatherings in suspension, 
upon pure glycerine. To increase the hardening of the animalcules, the 
liquid in excess is first removed and replaced by strong alcohol, by 
picrocarinine, or by green picrate of methyl, it is then poured gently 
on the glycerine, which, owing to its density, remains at the bottom 
of the vessel, but previously the liquid to be filtered must be briskly 
agitated so as to disengage the animalcules caught by their cilia in 
the matted fibres of the moulds. 

‘The Infusoria thus detached fall first to the bottom. The 
patches of mycelium which offer more surface and consequently more 
resistance do not sink, or sink much more slowly. Advantage is 
taken of this circumstance to decant the liquid with a pipette, and to 
collect from the bottom of the vessel the Infusoria which, being 

isolated, are best adapted for observation. 


* Bull. Soc. Zool. France, vi. (1881) pp. 36-37. 
Tt See this Journal, ii, (1879) p. 331 ; iii, (1880) p. 847. 


280 SUMMARY OF CURRENT RESEARCHES RELATING TO 


In default of osmic acid, filtered lemon juice may be employed ; 
but it is necessary to follow the operation closely in order to check at 
the right moment the action of the reagent, which should be employed 
in a strong dose, and which consequently would in the long run injure 
the extremely delicate tissues of the Infusoria. 

Impregnation by chloride of gold is generally successful after the 
action of lemon juice. Often, however, the pulverulent deposit gets 
entangled in the cilia of the Infusoria and obscures observation. Filtra- 
tion upon glycerine reduces this inconvenience. 

In conclusion, M. Certes indicates the process which he considers 
best for preserving the intestines of Batrachians with the object of 
examining the parasites they enclose. Having tied the intestine at 
the two extremities, it is washed in distilled water and placed in a 
solution of osmic acid (1-1000). After twenty-four hours’ immersion, 
this solution is replaced by strong alcohol or by glycerinated water. 
Under these conditions, Opaline and other inhabitants of the 
rectum of Batrachians may be kept undistorted till they can be 
examined. 

Tn a subsequent paper,* the author mentions that he has met with 
difficulties in the latter process. When the walls of the intestine are 
too thick or are too much filled by food, there is so great an absorption 
of the reagent that the Opaline and other parasitic Infusoria are 
dissolved under the action of the liquids of the organism or by the 
preservative liquids. He thinks it will be found sufficient to increase 
the strength of the osmic acid solution, and to slit the intestine 
longitudinally. 


Staining the Nucleus of Infusoria.j—A. Certes has already 
shownt the property possessed by cyanin or chinolin blue (and 
Bismarck brown) of staining living tissues, the nucleus of Infusoria 
not, however, appearing to be coloured either during life or even 
several hours after death. Dr. Henneguy having pointed out to him 
the analogous properties of a methyl violet, known as dahlia, M. Certes 
has repeated his experiments with several violets, and has found that, 
notwithstanding their very similar chemical composition, their action 
varies considerably. Some are always toxic, and for all species of 
Infusoria. Others only stain certain species out of those living in 
the same liquid. Others—and this is the special object of his further 
communication—stain the nucleus of living Infusoria, and more 
strongly than the rest of the protoplasm. In general with the violets in 
question, the cilia are always stained, and the liquid of the contractile 
vacuole often participates (so far as could be judged) in the general 
colouring. 

The phenomena of selection of the colouring matter in regard to 
the nucleus was clearly established, at first with B B B BB violet on 
Balantidiuwm from the intestine of Bombinetor igneus, and then on 
Paramecium, Vorticella, &c., with the same and dahlia violet. Gentian 


* Bull. Soc. Zool. France, vi. (1881) p. 228. 
¢ Ibid., pp. 226-7. 
t See this Journal, i. (1881) pp. 527, 694. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 281 


and 50 N violet on the contrary, notwithstanding their great colouring 
power, did not exhibit any selective action with the nuclei. 

As to the greater or less resistance which very closely allied 
species oppose to the action of the same reagent, the author mentions 
that he has found small species of Paramecium continue to live in- 
definitely without staining, whilst all the others of equal or greater 
size had entirely disappeared from the same liquid. 

The staining of the nucleus of the Infusoria is, the author 
(erroneously) says, “ a new fact, and it is so much the more interesting 
to note that the most recent researches demonstrate the prepon- 
derating part which the nucleus plays in the phenomena of nutrition 
and reproduction, and, if one may so say, in the government of the 
life of unicellular organisms.” 


Aniline Dyes and Vegetable Tissues,*—Mr. J. M. Macfarlane, in 
a paper on the action of some aniline dyes on vegetable tissues, records 
some of the more important methods arrived at. 

“ Staining of Laticiferous Vessels—Hvery botanist must have ex- 
perienced the difficulty of obtaining thoroughly good preparations of 
laticiferous vessels. Sachs recommends boiling in dilute potash ; but, 
while tolerably good sections may be obtained in this way, several 
difficulties are encountered. The points to be aimed at in preparing 
this tissue are (a) the coagulation of the latex, so that it may continue 
to fill the vessels; (b) the staining of the cut sections, so that the 
vessels may be distinctly differentiated from the surrounding cellular 
substance; (c) the successful mounting of these, so that the tint may 
be permanently retained. The first part of the process is best accom- 
plished by obtaining, for example, a large and entire root of Scorzonera, 
so that extensive bleeding may be prevented. A suitable sized bottle 
being filled with alcohol, pieces of the root from one to two inches in 
length are cut and immediately placed in it. Coagulation of the 
latex is quickly effected. After lying thus for a week or longer, 
sections are cut with the hand, or by aid of a microtome. Thesecond 
point is most important, and on its success the beauty of the object 
will depend. The sections are placed in alcoholic solution of saf- 
franine, obtained by dissolving 1 part of this dye in 800 parts 
spirit. After 18 to 24 hours, they are removed from the stain and 
decolorized by washing repeatedly in spirit. It will be found that 
the stain leaves the cellular tissues rapidly, while it is retained by 
the latex in the vessels. We will notice, lastly, the best method for 
mounting these. While such media as balsam or dammar would 
cause unnatural contraction, fluids, on the other hand—especially 
acetic acid solution—are apt to act slightly on the dye. I have 
found nothing to equal glycerine jelly, as it preserves the tint and is 
easily worked. 

Double Staining of Stems, dc—The dyes usually recommended for 
this purpose are rosaniline and iodine green; but saffranine and 
emeraldine are preferable, as the former is, for vegetable tissues, a 


* Trans. Bot. Soc. Edin., xiv. (1881) pp. 190-1. 


282 SUMMARY OF CURRENT RESEARCHES RELATING TO 


most permanent dye, while the latter imparts a brighter colour than 
iodine green. 

Staining of Cell Contents.—While some aniline dyes act specially 
on the thickened walls of cells, others are extremely useful for 
demonstrating the structure of protoplasm. Heliocin and naphthaline 
in this respect are valuable ; and eosin, though not an aniline dye, 
is equally so. For epidermis cells and ordinary parenchyma the 
latter is preferable. It is best prepared by dissolving 1 part in 1200 
of alcohol. The specimens are allowed to lie for 5 minutes in the 
stain, and are then washed in water and mounted in a cell with 
acetic acid, or Goadby’s solution. The cells of Spirogyra, however, 
have their minute structure beautifully revealed by treatment with 
heliocin. The following is the best method to adopt :—Decolorize the 
filaments by placing them in a 1 per cent. solution of chromic acid for 
two days; add then to the solution 1 part in 2000 of the dye, and 
shake slightly, so that it may dissolve equally. In an hour the 
filaments will be ready for examination or permanent preparation.” 


Indol as a reagent for Lignified Cell-membrane.*—Max Niggl 
gives a résumé of the observations of previous observers on the use of 
indol as a reagent for testing the lignified condition of the cell-wall, 
supplemented with additional observations of his own. 

If a section of a branch is treated with dilute hydrochloric acid, 
and an alcoholic solution of indol added, the lignified cells acquire a 
beautiful cherry-red colour, while the non-lignified cells of the cam- 
bium, cortex, and epidermis remain uncoloured. The use of hydro- 
chloric acid is, however, for several reasons inconvenient, and the 
author prefers the use of dilute sulphuric acid of sp. gr. 1°2 (1 vol. 
English sulphuric acid with 4 vols. water). The best mode of pro- 
cedure is as follows:—Pure indol is dissolved in warm water. The 
section is moistened with a drop of this solution, and covered with 
a coyer-elass. The indol is then removed by blotting-paper, and a 
drop or two of the dilute sulphuric acid run in. Wherever this 
comes into contact with the indol which permeates the section, the 
lignified cell-walls take a beautiful cherry-red, the sclerenchymatous 
cells even a purple colour, which is retained by the preparation for a 
considerable time. If the acid used is too concentrated, or the excess 
not removed, the colour passes, after some weeks, to brownish red. 

Among Thallophytes, Niggl found, by the use of this reagent, no 
trace of lignification in alge, or in the majority of fungi; it was only 
present in the cortical and medullary layers of a few lichens. 

In vascular plants the cuticle is as a rule uncoloured by indol. 
In many plants (contrary to the statement of other observers), the 
walls of the guard-cells of stomata appear to be strongly coloured. 
This is also the case with cork, except that in older cork-cells the 
middle lamella gives indications of lignification. With very few 
exceptions collenchyma also shows no colouring with indol. The 
author enters into considerable detail with regard to the colouring of 
the various elements of parenchyma, and of sclerenchyma. A charac- 


* Flora, Ixiv. (1881) pp. 545-59, 561-8. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 283 


teristic property of tracheids is the very early and strong develop- 
ment of lignification in their cell-walls. In the walls and disks of 
sieve-plates, on the contrary, indol produces not the least reaction. 

Protoplasm acquires a slight rose-colour with indol and sulphuric 
acid, but no differentiation of the nucleus is observable ; the contents 
of the stinging hairs of the nettle assume throughout a red colour. 
No effect is produced on the contents of resin-passages. 

The author concludes that the red colour imparted by indol and 
sulphuric acid is an unfailing test for the lignification of the cell- 
wall. 


English’s Method of Preserving Hymenomycetes and Wild 
Flowers.*—When we mention that the price of this book is 7s. 6d., 
and that each of the two sections only contains as much matter as two 
columns of the Times, it will be obvious that it cannot be abstracted 
without seriously interfering with its proprietor’s expected profits. 
We therefore confine ourselves to generalities. 

For Fungi, a double preservative compound is used, formed of 
British farina, methylated spirit and corrosive sublimate, oxalic acid and 
sulphur. There is also an “adjunct to the process,” formed of plaster 
of Paris and sulphur, for imbedding the specimens after the preserva- 
tive has been applied. The final process consists of varnishing. 
Waxing and colouring can also be adopted if desired, for which 
directions are given. 

The process for flowers (which has only been tried for two years) 
is to imbed them in plaster and lime as an absorbent, and gradually 
heat them up to 100° F. After dusting, they are varnished with 
similar varnish to that used for Fungi. 


Mounting Salicine Crystals.t—Dr. D. H. Briggs recommends 
the following process :— 

Clean the slide perfectly with ammonia, thén rinse with hot water 
and cleanse with ammonia again. 

Add to the salicine from one-tenth to one-twentieth its weight of 
pulverized gum arabic. Make a nearly saturated solution of the 
salicine and gum in distilled water, or in ice-water heated to the 
boiling point, and carefully filter the solution. Heat the solution to 
100° C. in the beaker, and pour the hot solution upon a still hotter (sic) 
slide, and drain off. Only a hot solution will give bright colours. 

Hold the slide, and watch for disks of crystals. As soon as these 
appear, place the slide on a cold iron block. 

A rim is put on the crystals by another heating over the lamp and 
another cooling on the iron. Without delay heat a drop of Canada 
balsam on a circular cover-glass, and apply the cover to the crystals, 
and fasten with white zinc cement on a turntable. ; 

The process described, if followed with care, will yield most 


* English, J. L.,‘A Manual for the Preservation of the Larger Fungi (Hymeno- 
mycetes) in their natural condition, by a new and approved Method; also a new 
Process for the Preservation of Wild Flowers.’ viii. and 41 pp. 8vo, Epping, 
1882. i 

y Amer. Mon. Micr. Journ., ii. (1881) pp. 227-8. 


284 SUMMARY OF CURRENT RESEARCHES RELATING TO 


excellent results; perfect rosettes cf crystals can be readily obtained, 
giving brilliant effects with polarized light. 


Bausch and Lomb Turntable.—We have no description of this 
turntable, but so far as we can gather from the drawing (Fig. 59), it 


Fic. 59. 


differs from other turntables in being provided with a hand rest, 
which can be adjusted to any convenient height. 


Griffith Cell.*—Mr. E. H. Griffith places the slide on a turntable, 
and with white-zine cement turns a circle on the centre if for a 
transparent mount, or a disk if for an opaque one, then centres to the 
circle or to the disk a common curtain ring, and immediately paints 
the ring with the cement, taking care not to push it from its position. 
When dry, the cement will hold the ring very firmly, so that there 
need be no fear that it will break off. 

If a shallow cell is desired the rings may be flattened easily ; or 
if a deep one is required, several rings may be securely fastened one 
above the other by painting each one in succession. If the cement 
does not flow readily add benzole; and in case the cell becomes 
rough, dip the brush in clear benzole and smooth it. Use a brush 
well filled with the cement to secure a smooth background. With 
a little practice a person may easily make fifty beautiful and practical 
white cells in one evening, and in a few hours they will be hard and 
ready for use. When the cover-glass is to be fastened, a little of the 


* Amer. Mon. Micr, Journ., iii. (1882) p. 9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 285 


cement is easily applied. When dry, the slide may be finished with 
colours prepared from tube paints mixed with benzole balsam, or 
with dammar and benzole. Before mounting, if a dark background is 
desired, a disk of asphalt of any desired size turned in the centre of 
the ring will be found convenient. Over the asphalt a small-sized 
cover-glass may be used for the object to be placed upon, or the 
asphalt may be covered with shellac when dry. The object may be 
fastened with gelatine or gum arabic, or made to adhere to the coat of 
shellac before it becomes dry. ) 


Bausch and Lomb Circle Cutter.*—This instrument for cutting 
circles of thin glass (Fig. 60) is intended to be attached to the 
turntable, by means of the screw shown at the right of the figure, so 


that the cutting point stands over the turning plate. The thin glass 
is placed upon the turntable and held by the central pin which then 
revolves with the glass. A gentle pressure causes the cutting point 
to touch the glass, and perfect circles can thus be readily obtained. 


Wax and Guttapercha in Dry Mounting.;—Prof. W. A. Rogers, 
of Harvard College Observatory, writes: — Notwithstanding the general 
condemnation of wax as a cement for covers in dry mountings, it is 
doubtful whether the objections urged against its use are altogether 
valid. I have had rather more than my share of experience in 
unsuccessful mountings of this class. During the past five or six 
years, I have been engaged upon the problem of the exact subdivision 
of any given unit into equal parts. Whatever success I may have 
gained in this direction has, I suspect, been somewhat more than 
counterbalanced by the deterioration of the ruled plates through the 
condensations which have formed under the covers. 

“T have lately collected quite a large number of these plates for 
the purpose of studying the characteristic defects of different kinds of 
mountings. As the result of this study, I have reached the conclusion 
that, for the most part, the primary cause of the condensations which 
form under the covers, is the moisture remaining upon the glass after 
the operation of mounting. No matter how thoroughly a glass slide 


* Amer. Mon. Micr. Journ., ii. (1881) pp. 225-6 (1 fig.). 
+ Ibid., p. 190. 


286 SUMMARY OF CURRENT RESEARCHES RELATING TO 


may be rubbed, if it is immediately held over a flame, a certain 
amount of moisture will appear.* 

“The evaporation from certain kinds of cement, without doubt 
aggravates the difficulty, and probably this is, in some cases, the 
independent cause of ‘sweating.’ 

“Nearly all of the slides examined were prepared in the following 
way: First, the cover-glass being held in position upon the slide by 
a clip, the moisture was expelled by heating. After the glass had 
become sufficiently cooled, small bits of white wax were placed around 
the edge of the cover-glass. The blunt point of a heated piece of 
metal was then passed slowly around the cover, and the melted wax 
flowed under it, far enough to hold it in position, The larger 
number of the slides prepared in this way were found to be well 
preserved. When, however, rings of cement were turned upon the 
slides, the protection was in almost every case less perfect. In every 
case in which shellac with anilin colouring was used, condensations 
on the under side of the cover-glass were found. The covers of 
several slides were removed, and in no case was there any sweating 
found upon the surface of the slide. 

“ About eighteen months ago, my attention was called to the use 
of sheet guttapercha rings for dry mounting. My first experience 
with these rings was not altogether satisfactory. It is now evident 
that I did not, at first, apply sufficient heat to expel all of the 
moisture between the cover and the slide. 

“ After an experience of several months, I am convinced that 
slides prepared in the following way, will remain in a perfect state of 
preservation for any length of time. Use guttapercha rings having 
a thickness of about one five-hundredth of an inch, and a diameter 
about one-twentieth of an inch less than that of the cover-glass. 
Hold the cover in position upon the ring with a light clip, while the 
guttapercha is being melted by a gentle heat. If too much heat is 
applied at first, the ring will lose its normal shape. After the gutta- 
percha is thoroughly melted, the slide should be heated sufficiently 
to expel every particle of moisture from under the cover. While the 
slide is hot apply white wax to the surface, the melted wax will run 
under the cover and will be stopped by the ring. After covering, 
the wax can be removed from the surface of the glass with turpentine. 

“JT shall esteem it a favour to be informed of any case in which a 
ruled plate, mounted in this way, has failed to remain in good 
condition.” 


Aeration of Aquaria.—Mr. J. W. Stephenson points out that it 
is impracticable to effectually aerate an aquarium in the way suggested 
by M. Kiinckel d’Herculais, ante, p. 131. The only really effectual 
method is to direct a very fine stream of water at a high velocity 
obliquely upon the surface of the aquarium at about the distance of 
an inch. By this means air in the finest possible state of subdivision 
is carried some distance below the surface with the result of ensuring 
a thorough aeration of the whole contents. 

* But will not moisture always appear on glass placed over a candle or other 


flame, through water being formed by the union of hydrogen with the oxygen of 
the air ?—Ep. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 287 


It was by this method that Mr. Stephenson was able to keep the 
water in his marine aquarium so pure that (in 1867) he hatched 
the spotted dog-fish and (in 1870) herring from the egg, which had 
not previously been accomplished. The former was hatched at the 
expiration of five months and nine days, and the latter of ten days, 
after the eggs were placed in the aquarium. 

The object of M. Kiinckel d’Herculais was apparently to devise 
a means of aerating a marine aquarium by means of a fall of fresh 
water, but the extra quantity of sea-water required to aerate an 
aquarium in the way proposed by Mr. Stephenson is not likely to 
present any difficulty, as it is easy to devise a plan by which a 
constant circulation can be maintained between the reservoir and the 
aquarium, without loss of water taking place. 

Reference may also be usefully made to an article by Mr. C. J. 
Watson on “a simple mode of aerating small marine aquaria,’ * 

in which he also describes a method of injecting air by the fall of a 
small quantity of fresh water. 


Boyp, J.—How to Make Wax-cells. 

[F. Barnard’s method, ITI. (1880) p. 860-1.] 

Sci.-Gossip, 1882, pp. 59-60. 

Britta, T.—Micro-fungi: when and where to find them. 

North. Microscopist, II. (1882) pp. 15-16. 

Bryan, G. H.—How to label Microscopie Slides. 

[Instead of one thin paper label at one end, use two made of slips of thick 
eard 1 in. by 3 to ? in.—they can then be placed one against the other 
without the glass of one slide touching the cover of the next, and hence 
there is no need of a cabinet, as any box of a suitable size will do.] 

Sci.-Gossip, 1882, p. 64. 

CrumpBateH, J. W.—Our Histological and Pathological Laboratories. II. 

[Views as to what should constitute a good working laboratory. ] 

Amer. Mon, Mier. Journ., U1. (1882) pp. 37-9. 

Cunnincuam, K. M.—Cleaning Diatoms. 

Amer. Mon. Micr, Journ., III. (1882) p. 14. 

D., A. J.—Improvements in Turntables. 

[Improvement by W. D. Smith in Kinné’s self-centering turntable— 
explanation unintelligible. | 

North. Microscopist, 11. (1882) pp. 74-5. 

Ecer, L.—Der Naturalien-Sammler. Praktische Anleitung zum Sammeln, 
Prapariren, Conserviren organischer und unorganischer Naturkérper. (The 
Collecting Naturalist. Practical Guide to the Collection, Preparation, and 
Preservation of organic and inorganic Natural Objects.) 5th Ed. 8yvo. Vienna, 
1882, pp. iii. and 221. 37 figs. 

Eveutsu, J. L.—A Manual for the Preservation of the Larger Fungi (Hymeno- 
mycetes) in their natural condition, by a new and approved Method; also a new 
Process for the Preservation of Wild Flowers. viii. and 41 pp. 8vo. Epping, 
1882. 

Hevrcet, H. van.—Immersion Fluids. 

[Transl. of paper in ‘ Bull. Soc. Belge Micr” See Appendix.] 

Amer. Mon. Micr. Journ., III. (1882) pp. 26-8. 

Hey, W. C.—Pond-collecting in Mid-winter. ; 

[Reports result of fishing some ponds near York on 2nd January.] 

Sci.-Gossip, 1882, p. 31. 

Laspeyres, H.—Ueber Stauroskope und Stauroskopische Methoden. (On 
Stauroscopes and Stauroscopic Methods.) 

Zeitschr. f. Instrumentenk., II. (1882) pp. 14-24 (3 figs.). 


* Midl. Natural., iii. (1880) p. 270. 


288 SUMMARY OF CURRENT RESEARCHES, ETC. 


Matsrancur, A.—Réactifs pour Vétude des Lichens. (Reagents for the 
study of Lichens.) Rev. Mycol., TV. (1882) pp. 9-10. 
Microscopic Curiosity. 
[Working steam-engine so small that a thimble will cover it. ] 
Amer. Mon, Mier, Journ., IIL. (1882) p. 19. 
Mounting Class of Manchester Microscopical Society. 
[Report of meeting. ] 
North. Microscopist, II. (1882) p. 40. 
Niect, M.—Das Indol ein Reagens auf verholzte Membranen. (Indol, a 
Reagent for Lignified Membranes.) 
(Abstr. of original article in ‘ Flora, LXIV. (1881) pp. 545-59, 61-6.] 
Bot. Centralbl., IX. (1882) pp. 284-5. 
Reinscu, H.—Detection of Borie Acid, Silica, and certain Metals by means of 
the Microscope. Journ. Chem. Soc., XLII., Abstracts, (1882) p. 245, 
from Ber. Deutsch. Chem. Soc., XIV. 2325-31. 
S., W. J.—Mounting for Hot Countries. 
(Inquiry for hints as to mounting in Canada Balsam and Dammar Varnish 
in India, and statement of difficulties experienced. ] 
Sci.-Gossip, 1882, pp. 39-40. 
Semper, C.—Bemerkungen zu Herrn Dr. Riehm’s Notiz “ Kine neue Methode 
der Trockenpraparation.” (Remarks on Dr. Riehm’s note on “a new method of 
dry preparation.” Zool. Anzeig., V. (1882) pp. 144-6. 
Stocker, G.—Preserving Flowers. Sci.-Gossip, 1882, pp. 65-6. 
STowELL, C. H.— Laboratory Notes (contd.). 
[Examination of sputa in suspected cases of phthisis, &c.] 
The Microscope, I. (1882) pp. 172-4 (1 fig.). 
Vorce, C. M.—The Detection of Adulteration in Food. V. Red-pepper and 
Turmeric. VI. Butter. 
Amer. Mon. Micr. Journ., III. (1882) pp. 1-6 (1 pl.) pp. 21-3 (5 figs.). 
Watmstey, W. H.—Some Hints on the Preparation and Mounting of Micro- 
scopic Objects. 2nd paper. 
[Mounting in balsam in cells. ] 
The Microscope, I. (1882) pp. 161-72 (7 figs. ). 
Warvd, E.—Micro-erystallization. 
[Describes the mode of preparation of Micro-crystals. ] 
North. Microscopist, II. (1882) pp. 25-33. 
Waite, M. C.—Examination of Blood-stains by Reflected Light. 
[ With Beck’s (vertical ?) illuminator and + in. objective. ] 
Amer. Mon. Micr, Journ., I11. (1882) p. 6. 
Wicurman, G. J.—Crystallized Fruit Salt. 
[Recommended as an object for the Polariscope.] 
Sci.- Gossip, 1882, p. 64. 
Woronin, —.—Les meilleurs Liquides Conservateurs pour les Préparations 
Microscopiques. (The best preservative liquids for microscopical preparations.) 
Rev. Mycol., TV. (1882) p. 71. 
ZIMMERMANN’S (O. E, R.) Mykologische (mikroskopische) Praparate. (Myco- 
logical—microscopical—preparations. ) 
{General description by G. W.] Ls 
Hedwigia, X XI. (1882) p. 5. 


( 289 ) 


PROCEEDINGS OF THE SOCIETY. 


Awnnuat Meetine oF 81H Fesrvuary, 1882, ar Kina’s Cottear, STRAND, 
W.C., THe Presipent (Proressor P. Martin Duncay, F.R.S.) mn 
THE CHAIR. 


The Minutes of the meeting of 11th January last were read and 
confirmed, and were signed by the President. 


The List of Donations (exclusive of exchanges and reprints) 
received since the last meeting was submitted, and the thanks of the 
Society given to the donors. 


From 
Reinsch, P. F.—Neue Untersuchungen iiber die Mikrostruktur 
der Steinkohle des Carbon, der Dyas und Trias. viii. and 
Ie pp.and 94 pls. ,4to. -Meipzig; 188.5 3) 3. oe 2 Yr Crisp: 
Tris-Diaphragm for Objectives .. .. .. «2 «ee . Mr. C. Collins. 
Sections of Sugar-caneand Palm .. .. .. .. .. Dr. B. W. Richardson. 


The President, referring to Professor Reinsch’s book, said it would 
be very desirable to have the mounted specimens which had been 
promised by him.* Without these it was impossible to determine 
whether the conclusions at which he had arrived were correct. 

Mr. Crisp said that with regard to Dr. Richardson’s slides it 

‘should be noted that the processes which he quoted as having been 
devised by Dr. Stirling were in reality due to Dr. H. Gibbes, whose 
descriptions had been taken by Dr. Stirling without acknowledgment 
of their original source. 

Mr. Crisp also called attention to the Iris-diaphragm for objectives 
presented by Mr. C. Collins. The use of such a diaphragm had been 
originally suggested by Dr. Royston-Pigott, but was now revived by 
Mr. G. E. Davis, for the special purpose of obtaining penetration 
with wide-angled objectives by reducing their aperture (see p. 262). 


The Treasurer, Dr. Beale, F.R.S., read his statement of the 
income and expenditure of the Society for the past year, which had 
been duly audited by the Auditors appointed at the last meeting 
(see p. 292). ; 

Dr. Gray moved that the statement be received and adopted; and 

Mr. Michael having seconded the motion, it was put from the 
chair and unanimously carried. 

A vote of thanks was given to the Treasurer and the Auditors. 


; The President, in pursuance of notice given at the previous 
meeting, read the proposed alteration in the Bye-law relating to the 
payment of subscriptions. He thought the alteration was one which 
would commend itself to the Fellows. 
Mr. Crisp then moved that the words from “ Fellows” to “ year ” 


* See Journal, i. (1881) p. 712. 
Ser. 2.—Vot. II. U 


290 PROCEEDINGS OF THE SOCIETY. 


inclusive be omitted from Bye-law No. 6a,} and the following inserted: 
— «A Fellow elected in any month subsequent to February shall not, 
“however, be called upon for the whole subscription for the current 
“year, but for a proportional part thereof only ; that is, if elected in 
“March or April he shall pay one pound fifteen shillings, in May or 
“ June one pound eight shillings, in October fourteen shillings, or in 
“ November or December seven shillings.” 
This was seconded by Mr. T. Charters White, and carried. 


The Report of the Council was read by the President (see p. 293). 

Mr. T. Charters White moved that the report be received and 
adopted and printed in the usual way, and the motion having been 
duly seconded, was put to the Meeting, and carried unanimously. 


The List of Fellows proposed as Officers and Council for the 
ensuing year was read as follows :— 

President—Prof. P. Martin Duncan, M.B., F.R.S. 

Vice-Presidents—Prof. F. M. Balfour, M.A., F.R.S.; *Robert 
Braithwaite, Esq., M.D., M.R.C.S., F.L.S.; *Robert Hudson, Esq., 
F.RS., F.L.S.; John Ware Stephenson, Esq., F.R.A.S. 

Treasurer—Lionel 8. Beale, Esq., M.B., F.R.C.P., F.R.S. 

Secretaries—Charles Stewart, Esq., M.R.C.S., F.LS.; Frank 
Crisp, Esq., LL.B., B.A., V.P.L.S. 

Twelve other Members of Council —*Ludwig Dreyfus, Esq. ; 
Charles James Fox, Esq.; James Glaisher, Esq., F.R.S., F.R.ASS. ; 
*J. William Groves, Esq.; A. de Souza Guimaraens, Esq.; John E. 
Ingpen, Esq.; John Mayall, Hsq., jun.; Albert D. Michael, Esq., 
F.L.S.; *John Millar, Esq., L.R.C.P. Edin., F.L.S.; *William 
Thomas Suffolk, Esq.; Frederic H. Ward, Esq., M.R.C.S.; T. 
Charters White, Esq., M.R.C.S., F.L.S. 

Mr. Beck and Dr. Gibbes having been appointed Scrutineers, pro- 
ceeded to take the ballot, and subsequently reported that the above- 
mentioned Fellows were all duly elected. A vote of thanks to the 
Scrutineers was unanimously carried. 


Mr. Beck said it had been usual to regard a vote of thanks to the 
Secretaries as a matter of course, but he thought that at no previous 
time did they so much deserve that a hearty vote of thanks should be 
offered to them. The Society was very greatly indebted for their 
services, and it was not as a mere matter of form that he made the 
' proposition that they should be thanked for the able manner in which 
the business of the Society was conducted. 

The President thought there could be no difference of opinion 
upon this matter. The Secretaries were the very life and soul of the 
Society, and most heartily deserved their thanks. The motion was 
then put from the chair, and carried by acclamation. 

Mr. Crisp in returning thanks for the vote on behalf of himself 


t+ See Journal, iii. (1880) p. 736. 
* Have not held during the preceding year the office for which they were 
nominated. 


PROCEEDINGS OF THE SOCIETY. 291 


and his co-secretary, said that he felt there should be an amendment to 
the proposition so as to make it include the President and the other 
Officers of the Society instead of singling out the Secretaries alone. The 
President in particular had been most indefatigable in the attention 
which he had given to the affairs of the Society, and had especially 
distinguished himself by the way in which he had added by his 
comments to the interest of the matters brought before their meetings. 
There was he knew a very general desire that his term of office might 
be an extended one. 


The President then read his Annual Address, which was warmly 
applauded by an appreciative audience (see p. 145). 

Mr. Ingpen said he had much pleasure in proposing a vote of 
thanks to the President for his able and interesting address. He was 
sure that those who had followed the revival of the discussion of the 
aperture question would thoroughly agree that the last year had, as 
the President had observed, marked an important epoch, in that it had 
placed the matter on its true scientific basis, and had exposed the 
strange fallacies by which the previous consideration of the subject 
had been confused. The Address was one which he felt sure they 
would all be pleased to read when printed, and to remember. For his 
own part, he would venture to express the hope that the President 
would carry out his intention of continuing his record of progress in 
a similar manner at a future time. 

Dr. Braithwaite having seconded the motion, Mr. Ingpen put it 
to the Meeting, and declared it carried by acclamation. 

The President thanked the Fellows for the vote of thanks and 
also for the honour which they had done him in again electing him 
President. He had at first been doubtful as to how he should succeed 
in that office, for although he had occupied the Chair in other societies, 
he had been prevented from attending the meetings of this Society. 
He could only say that he would do his best during the term of office 
for which they had re-elected him, and hoped that at its termination 
he should receive their approval. 


New Fellow.—Mr. W. A. Thoms was elected an Ordinary 
Fellow. 


SOCIETY. 


PROCEEDINGS OF THE 


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PROCEEDINGS OF THE SOCIETY. 293 


REPORT OF THE COUNCIL 
presented to the Annual Meeting on 8th February, 1882. 


New Fellows. 


Having regard to the large number of new Fellows elected during 
the years 1879 and 1880, it might have been fairly expected that the 
new elections would now show some diminution. The Council are, 
however, gratified to find that during the past year 51 Ordinary 
Fellows were elected, as against 47 in 1880 and 58 in 1879. 

Twenty-four Fellows have died or resigned (1 compounder, 
22 subscribers, and 1 Honorary Fellow), and the list now stands as 
follows :—501 Ordinary, 49 Honorary, and 83 Ex-Officio Fellows. 

The greatest number of Ordinary Fellows at any previous period 
of the Society’s existence was 452. 


Finances. 


The income of the Society (excluding admission fees) now amounts 
to 728/., being 636/. 6s. derived from subscriptions, and 91/. 14s. from 
investments. In accordance with the determination come to at the 
Annual Meeting in 1881, it is not intended in future to invest Com- 
positions, except in the contingency mentioned in the Council’s last 
Report. 

Library, &c. 

The additions to the Library are now so numerous that there is a 
difficulty in providing space for them on the shelves, and it is feared 
that the only remedy will be to discontinue some of the exchanges. 

A catalogue of the Library has been prepared by the Assistant- 
Secretary, and checked by Mr. Fox, who has also kindly undertaken 
to prepare a catalogue of the property of the Society generally. 


Meetings. 

The attendance at the meetings of the Society has been well main- 
tained, and if the Council were furnished with a greater number of 
papers, recording the results of original work on the part of Fellows, 
the position of the Society would leave hardly anything to be 


desired. 
The Journal. 


In accordance with the desire expressed by the Council, the last 
volume of the Journal has been somewhat reduced, and would have 
been brought within the limit of 1000 pages but for the pressure 
caused by the revived discussion of the aperture question. 

With the completion of that volume Mr. Crisp’s arrangement for 
the honorary editorship of the Journal terminated. The Council 
“passed a unanimous resolution expressing their thanks for his 
valuable services in conducting and editing the Journal, and for the 
great liberality he had displayed in its production. Under the 

‘ 


294 PROOEEDINGS OF THE SOOIETY. 


special circumstances which existed, the Council did not feel them- 
selves able to invite Mr. Crisp to continue to act as Editor; but 
having appointed a committee to confer with him on the subject, they 
were gratified to find that he was willing to continue the existing 
arrangement for two years further. The Council are sure that the 
Society will cordially endorse both their resolution as to the past 
conduct of the Journal and their satisfaction that it will be continued 
for a further period. ‘The thanks of the Society are also due to the 
Associate Editors for their services in connection with the Journal. 


Mertine or 8rx Marcu, 1882, ar Kine’s Cotter, Srranp, W.C., 
Tue Presmenrt (Proresson P. Martin Dunoan, F.R.S.) in 
THE CHAIR. 


The Minutes of the Annual Meeting of 8th February last were 
read and confirmed, and were signed by the President. 


The List of Donations (exclusive of exchanges and reprints) 
received since the last meeting was submitted, and the thanks of the 
Society given to the donors. 


Arnold, J. A. F.—Die neueren Erfindungen und Verbesserungen From 

in betreff der Optischen Instrumente. 232 pp. and 4 pls.. 

(hoy, “Qyaralllinnorsiven, ISES)55 fA) eg 66 soo on ot Mr. Crisp. 
Diatomaceous Earths from California .. .. .. .. .. Mr. H, G. Hanks, 


The President said that the Council had approved (under the 
15th Bye-law) the recommendations of two Honorary Fellows to fill 
the vacancies in the list caused by the deaths of Messrs. Schleiden and 
Schwann, viz. (1) M. C. Robin, of France, well known as an histologist 
and microscopist, and the author of the ‘ Traité du Microscope et des 
Injections’; and (2) Dr. L. Dippel, of Germany, also an eminent 
microscopist, and the author of ‘Das Mikroskop und seine Anwend- 
ung, in which not only the Microscope but the histology of plants 
is ably dealt with. 


Mr. J. Mayall, jun., described Wenham’s Universal Inclining 
and Rotating Microscope exhibited by Messrs. Ross (see p. 255). 


Mr. Crisp exhibited and described the Bausch and Lomb Optical 
Company’s Trichinoscope (see p. 258); the “ Hampden” Portable 
Simple Microscope, lent by Sir John Lubbock, Bart. (see p. 258) ; 
two cheap American “ Dissecting Microscopes”; one of Fasoldt’s 
19-band test-plates; Aylward’s “ Patent Micro-slide”; and Stokes’s 
Tadpole-slide (see p. 110). 


Mr. R. J. Lecky’s note as to the origin of the glutinous character 
of spiders’ webs was read. 


Mr. Crisp described the composition of the two immersion fluids 
sent by Dr. Van Heurck, and exhibited at the December meeting (see 
pp. 183 and 264). 


PROCEEDINGS OF THE SOCIETY. 995 


Dr. Ord described and figured on the black-board certain sym- 
metrically-placed large nerve-fibres which he had discovered in the 
spinal cord of the pike, the axis-cylinders of these animals being of 
enormous size, at least seven or eight times the diameter of the largest 
axis-cylinder found in the human spinal cord, or so far as is known 
in any of the higher mammalia. 

Mr. Stewart said that the presence of the large fibre described by 
Dr. Ord with its proportionately large axis-cylinder was a matter of 
considerable interest, and that he looked forward to Dr. Ord’s further 
investigations, so that its connections might be determined and data 
derived for understanding its chief function. 

The President said they were greatly indebted to Dr. Ord for his 
description and drawings, and expressed the hope that he would be 
able to lay before them during the present session the results of his 
further investigations so that they might be published in proper 
- form. 

Dr. Ord, in reply to a question as to the way in which he prepared 
the cords referred to, said that they were partly prepared with strong 
spirit, and partly with Miuller’s fluid with a considerably long immer- 
sion. For those that he was now preparing he used a bichromate of 
ammonium solution. 


Mr. Crisp referred to the objection that had been raised to homo- 
geneous-immersion objectives as regards their liability to be scratched 
(see p. 264). 

Dr. Edmunds said that he had used homogeneous lenses from 
their earliest introduction, and that the surfaces of the front lenses 
were still as highly polished, and the objectives in fact in all respects 
as perfect now as they were at first. 


Dr. A. S. Mercer’s views as to stereoscopic vision with non- 
stereoscopic binocular arrangements were explained by Mr. Crisp 
(see p. 271). 


Mr. Stewart described and exhibited a gold-stained preparation 
of the crop of a snail, showing the nerve-termination having occa- 
sional large nerve-cells (in groups of rarely more than two) connected 
with it. From these large fibres spring, and there were others much 
smaller with groups of nerve-cells, from which again proceeded 
fibres of exceeding minuteness, forming a dense intercommunication 
with a few mostly elongated nerve-cells connected with them. The 
latter was apparently the terminal nerve-plexus, and lay immediately 
beneath the epithelial lining of the pharynx. 

The President said he was grateful to Mr. Stewart for so inte- 
resting a demonstration, which opened up a field well deserving the 
attention of some of the younger Fellows. 

Mr. Stewart said that he did not in these experiments recognize 
the termination in the muscle-fibres, but that some of them do so 
there was no doubt. 


2.96 PROCEEDINGS OF THE SOCIETY. 


Mr. Crisp, referring to a paragraph in the President's Address, 
explained the misconception involved in the use of miniatured images, 
so far as regards the supposition that thereby very minute fractions 
of an inch were visible. 


The President announced that the Second Conversazione of the 
session would be held on the 26th April. 


The following Instruments, Objects, &c., were exhibited :— 

Mr. Bolton :—Various Rotifers. 

Mr. Crisp:—(1) Bausch and Lomb Optical Co.’s Trichinoscope 
(p. 258). (2) Two cheap American “ Dissecting Microscopes.” (3) 
Fasoldt’s 19-band Test-plate. (4) Aylward’s “ Patent Micro-Slide.” 
(5) Stokes’ Tadpole Slide (p. 110). 

Sir John Lubbock, Bart.:—The “Hampden” Portable Simple 
Microscope (p. 258). 

Dr. Ord :—Preparations illustrating his paper. 

Messrs. Ross:—Wenham’s Universal Inclining and Rotating 
Microscope (p. 255). 

Mr. Stewart :—Pharynx of snail. 


New Fellows.—The following were elected Ordinary Fellows :— 
Messrs. William A. Delferier, Wilson Noble, and Charles N. Peal. 


Water W. Reeves, 
Assist.-Secretary. 


fay OU 1S ISU UN Une seconGd weanesaay or 
February, April, June, August, October, and December. 


Ser. II. To Non-Fellows, 
3 Evel. II. Part 3. JUNE, 1882. i Price 4s. 
JOURNAL 
z OF THE 
ROYAL 
CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, 
AND A SUMMARY OF CURRENT RESEARCHES RELATING TO 
5 ZOOLOGY AND BOTANYDT | 
Ee (principally Invertebrata and Cryptogamia), 
- MICROSCOPY, éc- | 
Ldited by 
FRANK CRISP, LL.B., B.A., 7 
One of the Secretaries of the Society 
and a Vice-President and Treasurer of the Linnean Society of London ; | 
-- -\ WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND 
4 BOW, BENNETT, M.A., B.Sc., - F, JEFFREY BELL, M.A, 
r Lecturer on Botany at St, Thomas's Hospital, Professor of Comparative Anatomy in King’s College, 
§. O, RIDLEY, M.A., of the British Museum, asp JOHN MAYALL, Joen., 
a FELLOWS OF THE SOCIETY. 
i | 
: 
s 


nee WILLIAMS & NORGATE, 3 
Be LONDON AND EDINBURGH. Sei, oy MEL 


Fo 


; a - : “ : < 
a BY WM. CLOWES AND SONS, LIMITED,] = [STAMFORD STREET AND CHARING CROSS. 
er 


iia 


2.) 


JOURNAL 


OF THE 


ROYAL MICROSCOPICAL SOCIETY. 


Ser. 2.—VoO.L. II: PART 8. 
(JUNE, 1882.) 


CONTENTS, 9 a 


TRANSACTIONS OF THE SoClETY— 


VIL.—Nore on THE SPICULES FOUND IN THE AMBULACRAL TUBES OF — 


THE REGULAR Honinomes. By Professor F. Jeffrey Bell, 
MLAS PRIMES CPA N 2) (76 Gee Ae ot, eee nl oe ee 


VIII.—Tue Reation or APERTURE AND PowER IN THE Microscope. 


By Professor Abbe, Hon. F.R.M.S. 


1X.—Tue Bacrerta or Davarye’s Suptrommta. By G. F. Dowdes- ints 


well, M.A., FLR.MLS., F.C.S., &e. 4.0 6. ee a a 


Summary. oF CURRENT RESEAROHES RELATING TO ‘ZooLOGY AND 
Borany (PRINCIPALLY INVERTEBRATA AND CrYPTOGAMIA), Micro- 


scopy, &c., INCLUDING ORIGINAL COMMUNICATIONS FROM Funtows : 


AND “OTHMBE So as cp Bed sevens Ain ad TE Vee ace 


PAY : $a. Seah 
Germinal Layers'of the Chick... ° 402 soo: Gen e's gs eh et ae 
Development of Lepidosteus a6 wine aa 0 8 ee ale ee 
Spermatogenesis in Vertebrates and Annelids BS. OS Ea We PEO 
Cell-structure S Bee Aeshna slat od ae A RO 
Theory of Ameboid Movements... Re ores TR eae Piney ee 


Distinctions between Organisms and Minerals... : 
“ Symbiosis of Animals with Plants”—Chlor aphylicorpuscles and Aint 
Deposits of Spongilla and Hydra 


Palzontological Significance of the Tracks of Different Invertebrates . ae $ oe 


Lymph of Invertebrates... Bera ree ee Hommes ec geen 
“Development of the Cephalopoda do hee gc ae eh eee ae 

_ Development of the Oyster... Ripard tee er ctr tie 
Abortion of Reproductive Organs of | Vitrina xe Boe t Rane sae 
Morphology of the pata ce he Pee pipe TG Say ehon co 
New Synascidian.. .: CR hee eee he esehaeeanas 
Alternation of Generations in Doliolum ..: ©. NSPE Stee: Orta! PS 
Nervous System of the zene Hé NES Rw ence ier eh 
Occident Ants .. Pile Ge akan Maa thas ty de Se 
Pycnogonida eee oe se ae os ee NAS sR hs : os a ye 
Spithers? Webs 5 ico ete Ss Ree ae gees Ta ra re oe Sa bo 
Limulus a Crustacean... Oe SSR ee ee A a 
Segmental Organs in Tsopoda comer PEP MAA? A Abe eae ee aT tT 
Bopyridz oo Sr rat 8 wee se Ke 2, 


Peculiar mode of Cop ulation in Mamie Dendroowia teeta Se ea g 
Classification of the Not aiokcaduben? Baek Caer Reece ee Th 
Relations of the Platyhelminthes .. 4. eeu te 
Entozoa confounded with Trichin# .. se) us as ue ae ne os 
Life-History of the Liver Fhike 0. 2000 ne ae be a 
Excretory Apparatus of rains Geiicclage sated eee a hes ea 
_ New Parasites .. odo doh pega eg Pokal ORS te seal ace 


(3) 


Summary or Current Researones, &c.—continued. 


~ Tube of Stephanoceros Hichorntt = .. 1s sn ne ae en 

Structure of Pedicellariz ME CPSs LRN PAA Dee 

Circulating Apparatus of Starfishes.. ane Pr eh Cony teas Pre are tae N 

Genital Passage: of Asterias Apc PER EON Peeps OTTey adler 

Chaculsnta Pron pende. cece fan fee op node uae Kes, Se ah wee 

Sponges of the Gulf of Triest .. 1 vee ue ne ne 

Spongiophaga in Fresh-water Sponges SRcanee Pina Na paler shoe 

Neto Fresh-water Sponges... 15 ve es be ne) hw oe) ee 

Organization of the Cilio -flagellata Fe apron Ma GLEE SP ae 

Infusorian with Spicular Skeleton 1. oe ss ne ees 

Contractile Vacuole of Vorticella .. 10 a0 es ae oe 

* Geographical Distribution of pees: A cer ue eA Sea 
Classification of the Gregarimda .. Ponce see DCs 

_ Psorospermiz in Man,, +6 ss 8 as ss 

Myxosporidia _.. a 

Morphology of Protozoa A ener sie elu, fata 

TLGZO0T CANAACNEE ina Se en Paw Na Bakes 


Borany. 


Ghorecal Difference between Dead and Living Protoplasm .. 

Occurrence of Aldehydes in Chlorophyllaceous Plante ..  .. 

~ Organ not hitherto described in the Vegetable Embryo .. 
Studies of Protoplasm.. .. i 
Composition of the Protoplasm of Zthalium septicum ss 
Properties of the Protoplasm in Urtiea- urens. , 
Fertilization of Salvia splendens ..- ss once wen 
Reproductiwe Organs of Loranthacee .. .. Spectres 

- Structure and Mode of Formation of Spermatozoids Gat atte eas 
Cell-nucleus in the Mother-cells of the Pollen of Liliacee §.. ,. 
Crystalloids in the Cell-nuclet of Pinguicula and Utricularia 

_ Cystoliths in Momordica wt Slaw imme a eee Tee cig ‘i 

 Sphero- crystals 


‘Structure of Starch-grains.. Pes IU gee 2 ss 
Assimilating Tissue... Reo Se iene ce Dy 


Fibrovascular Bundles of Monocotyledons Wa wince ec Wienges 
Steve-Tubes .. SP, Nacerihygx PeNT nS Morpeth 
Structure and Functions of Stomata.. .. sevineekg cea tatas 
Stomata of Stapelia: .. 

Influences of External Forces on the Direction of Growth 


Water Distribution in Plants .~. Boh ont creat 


Causes of the Movement of Water in ‘Plants - = 
* Compass-flowers” 


_ Relation of Nutrition to # the Distribution of the Sexual Organs 0 


Prothallium of Ferns... 
- Cell-division and Development of the Embryo of Isoctes lacustris... 
Chemical Composition of Mosses 


Influence of Oxygen on the Deoslupiituno} of the Lower Fungi a 


~Chetomium .. 
- . Completoria complens, a Parasite on the Prothaltium m of Ferns 
' Rehm’s Ascomycetes .. 
~ Destruction of Insects by Yeast .. ; 
Development of Fungi on the Outside and Inside of Hens’ Eqge .. 
Biology of Bacteria 
Influence of Concussion on ‘the Development of the Schizomycetes .. 
Experimental Production of the Bacteria of the Catile-distemper .. 
Bacteria of Caticasian Milk Ferment — .. 20 un os 
Parasitic Organisms of Dressings ... 2. 2. se tnt 
_ Parasitic Nature of Cholera... ke 
POPU GHSANE OF LWUEPCUNOREE Wace? twas noo oe su, fae eee ae py oe 
BHaperimental:Puberctslosia is 2 tre sas vai ob ae awd tk 
Etiology of Tubercular Disease... a 
Structure and Development of the A pothecia. of Lichens a 
Structure of Crustaceous Lichens  .. Caio tga s weaetias 
nogonium and the Schwendenerian Theory . ESA ers awed aero 
eee aie ol Marne Ale Riaiat antic lane iam i OR any ree e tiea 


ve 


C2 
Summary or Current Reseancurs, Soa 
Phyllosiphon Arisari Bas geo tWas sad 3 6h) aa. awe en cone eae po eee ene 


Structure of Corallina “ eee 
Impurities of Drinking Water caused d by Vegetable Growth. 4. a 
Fossil Siphone® ..... Das eas eed OES. GE ee 
oP alivehbeniy a Abaya es oO TE ras eae aes Ge abs ee ee 
Motion of Diatoms bi Mpeg det FPR ee pee oe eee 
Microscopy. 
Griffith's Portable Microscope .. rates niet re re aie eee a st 
Parkes’ Class Microscope (Fig. 61) . wok od Dee Ree re 


Pringsheim’s Photo-chemical Microscope (Fig. 62) Ee 
Waechter’s (or Engel’s) Class or Demonstrating Mieroscope Figs 6 63 J aad o4 


Wasserlein’s Saccharometer Microscope (Fig. 65)... Sa 39 
Wenham’s Universal Inclining and Rotating Microscope bs acs eee 
Briicke Lens.. —.. SS Aes 
Bausch and Lomb Handy Dissecting “Microscope (Fig. 86). jae Ste 
Excelsior Pocket and Dissecting Microscope (Fig. 67) .. Aes i 


Hartnack’s Drawing Apparatus (His’s Embryograph) ig: 88) «. aT aes 
Drawing from the Microscope .. i. 

Ulmer’s Silk Thread Movement (Figs. 69-72). ; 

Diaphragms for Limiting the Apertures of Objectives (Fig. 73): 
Correction-adjustment for Homogeneous-immersion Objectives .. +«.  v 
Hitcheock’s Modified Form of Vertical Illwminator ... «1 we te 
Flesch’s Finder (Figs. 74 and 75) ..  .. Tei Pe yise site 
Burnett's Rotating Tive-Box  .. ae sae Cag ope Ree 
Schklarewski’s Hot-water Stage (Fig. 76). Bk? i Sp ea ne ee eee 
Abbe’s Condenser (Figs. 77. and 78) s.0 <5 6.) weve be ee ae 
Bausch and Lomb's Immersion Illuminator 2. 0s ss eee es? 


. 
. * 


Bausch’s Paraboloid .. Es Sek a hoe IR eee ee 
Browning’s Simple Heliostat (Fig. 79) Pa pe ata a a 
Hayem and Nachet’s pear Hematometer (Figs 80-82)... paca eras 


Fasoldt’s Test-plate .. -. Sea pier ys. e. ess 
High Resolving-power. 0.40 ek 68 te ae ae ee oe ie 
Binocular Microscopes . Sway ges OREN he EY ae Opes Mura Pe ae oe Sek Ny: 
Electric Light in Microscopy PR REMY Ce ate hoe whe 
Definition of Natural and Artificial Objects fe ihtaper i Sire heey eas kee name 
Cole’s “ Studies in Microscopical Science”. ws su te ue eae ae 
Journal of the Postal Misroscopical Society... 9 +6 32 ae ne ene 


. Colouring Living Microscopical Organisms .. Ree Ree 
Mounting Histological Preparations with Carbolic “Acid and Balsam... Fee 
Differentiating Motor and Sensory Nerves... «ss ee se Pee 
Preparing Nerve-fibrils of the Brain -. wu ce tenes 2 one 
Cochineal. Carmine-solution .. apace gine eaet ae tale 
Polarized Light as an Addition to Staining 9 Rei eh OM hae ce 
Wickersheimer’s Preservative ee Dele ?s eon ies feng Sot ere om 
Preparing Hemoglobin Crystals’ - pai mgt oo eae boar Cae 
Preserving FONG se oe ae SA Ra Lee th Oe e: 
Cleaning Diatoms * oe oe A on ee epg ee, o* Sa o- 
Gaule’s Method of’ Imbedaing eae ¥% 
Williams’ Freezing Microtome adapted for Use with Ether ig. 88) ee _ £30 
Swift and Son's Improved Microtome (Bigs. 84-87) +. swe be ae 
Bausch and Lomb’s Standard Sey-Cntering iahiowi As Skene alae ide 
Orystallized Fruit Salt 3.0 ve ss, be tigiet See Owes emus 


Proorepines. or THE Socery =.) ake os 


conN 
or 
NS 


Royal Alicroscopical Society. 


IMBETINGS FOR 1882 


Av 8 P.M. 


1882. Wreednestsy, JANUABY {20 Sortie oy ciate Ss eo LE 


Ge FEBRUARY .. yy Serine 


(Annual Meeting for Election of Ofte cers 
and Council.) 


is ae A MAROR ee ce Se San ee Ria ee 
Bs ng i APR ee Toa CO alge pega ee 
es Mawes ee ee eee a, NO 

5 SEN OE ag oe it Ne 
dont: OUTOBER Be ete eet as © oe ge eC © 
: ‘ey AINE CW OBR 5 Se een ag I A) aR 
: Hs ADRURMBRR 15 8 oes eek a eee de 


“THE Be SOCIETY ” STANDARD SCREW. 


The Council have made SE I for a further supply of Gauges 
: and Screw-tools for the “Soomry” Stanparp Screw for Oxszorives, 


ue The price of the set (consisting of Gauge and pair of Screw-tools) is 
_ 12. 6d. (post free 128, 10d. ). Applications for setis should be made to the 
> Assistant-Secretary. | 

o For an explanation. of the intended use of the cane, see Journal of the 
Pads pees PP. fase 9 


ue _ ADVERTISEMENTS FOR THE JOURNAL. 


; Mn. Ceanes piace of 75, Chancery Lane: W.C., is the authorized 
Agent sas Collector for Advertising Accounts on behalf of the Society. 


8.9 


COUNCIL. 


ELECTED 8th FEBRUARY, 1882. 


PRESIDENT. 
Pror. P. Marti Duncan, M.B., F.B.S. 


VICE-PRESIDENTS. 
Pror. F. M. Baurour, M.A., F.RS. 


Rozert Brarrnwaite, Esq., M. D., M.B.CS., F.LS. 


Rosert Hunson, Esq., F.BS., FLS. 
Joun Ware SrepHenson, Hsq., F.R.A:S. 


~_ 


TREASURER. 
Lionet §. Beatz, Esq., M.B., F.R.C.P., FBS. 


SECRETARIES, 
Cuartes Srewart, Esq., M.R.CS., F.LS. 


Franx Case, Esq, LLB, BA, VP. & Tams. LS, 


Twelve other MEMBERS of COUNCIL. — 


Lupwie Dreyrvs, Esq. 
Cartes Jamus Fox, Esq. 
James GiaisHer, Esq., F.RS., F.RAS. 
J. Wu11am Groves, Esq. 
A. pE Souza Guimararns, Esq. 
Joun E, Inapen, Esq. 
Joon Mayan, Esq., Jun. 
Apert D. Micnazn, Esq., F. L. S. 
Joun Muar, Esq., L.R.C.P.Edin., ELS. 
Witx1Am Tuomas Surroxx, Esq. 
‘Freverice H. Warp, Esq., M. R. CS. 


T. Ouaxrens Wie, Eg, MROS, PLS. : 


ule ae Nig oi Fe > fee ps 
SP NE SR ae PRT a 


PSI, OD Sen A EOS 


- '% J 
iy UP Mae re 
Sy Sens a Mla Sy | Sy 


Lee) 


I. Numerical Aperture Table. 


The “ APERTURE” of an optical instrument indicates its greater or less capacity for receiving rays from the object and 
transmitting them to the image, and the aperture of a Microscope objective is therefore determined by the ratio 
between its focal length and the diameter of the emergent pencil at the plane of its emergence—that is, the utilized 
_ diameter of a single-lens objective or of the back lens of acompound objective. 
[his ratio is expressed for all media and in all cases by m sin u, n being the refractive index of the medium and wu the 
 semi-angle of aperture, ‘The value of n sin w for any particular case is the ‘‘ numerical aperture” of the objective, 


Be - Diameters of the 


Pepe Angle of Aperture (= 2 u). ; Theoretical Pane? 
Wace Lees of ations | seu mmerical| | waim. |Gomapmone| ne |  RRMME | wating 
Bea ces ; d Aperture. Dry ater- | Homogeneous-, nating | _— Power, in Powen 
Objectives of the same (n sin u=a.) | Objectives Immersion, Immersion | Power. | Lines toan Inch.) 
» _~ Power (4 in.) Spee: uect 5 * | Objectives.| “Objectives. | (a2.) | (A=0°5269 p (-) 
from 0°50 to 1-52 N. A, = }) a= 1*33.), (m = 1752) | =line E.) | a 
| 
1°52 |. 180° - 0/°| 2°310) 146,528 "658 
-. 1°50 HSE GLE De | 2°240 | 144,600 *667 
- 1°48 | 153°: 39" | 2-190) 142,672 *676 
1-46 | 147° 42’ | 2-132| 140,744 | +685 
1°44 142° 40’ | 2°074 138,816 694 
1:42 oe 138° 12’ |2°016|- 136,888 “704 
1°40 | oe 134° 10’ |1°960| 134,960 "714 
1°38 ee 130° 26’ | 1-904 133, 032 *725 
1:36 126° 57’ | 1-850 131,104 “735 
1°34 5 123° 40’ | 1°796 129,176 “746 
1°33 180°. 0’; 122° 6’ |1°770) 128,212 *Td2 
1°32 165° 56’| 120° 337 /1°742 127,248 “758 
1°30 155° 38’) 117° 34’ | 1°690 125,320 -769 
1:28 148° 28'| 114° 44’ |1°638) 123,392 *781 
1°26 142° 39’| 111° 59’ | 1°588 121,464 “794 
1:24 137° 36’; 109° 20’ | 17538 | 119,536 *806 
1:22 Ba 138° 4’| 106° 45’ | 1-488 117,608 *820 
1°20 oe 128° 55’) 104° 15’ | 1-440 | 115,680 *833 
LAG | Sad 125°. 3’, 101° 50’ |1°392; 113,752 847 
BG It eae ea 121° 26'| 99° 29" |1°346 111,824 * 862 
1:14 118° 00'| 97° 11/|1°300| 109,896 | -877 
1-12 114° 44’| 94° 56’ |1°254| 107,968 °893 
ALO 111° 36’. 92° 43’ }1°210| 106,040 *909 
1-08 108° 36’. 90° 33’ |1°166| 104,112 *926 
1:06 105° 42’) 88° 26’ | 1-124 102,184 *943 
1°04 102° 53’|. 86° 21’ | 1-082 100,256 "962 
1:02 a 100° 10’; 84° 18’ | 1-040 98,328 “980 
1-00 180° 0’ | 97° 81’|. 82° 17' | 1-000 96,400 | 1:000 
0°98 T57°. 2K] 94° 56") 80°17! | =960| 94,472 1:020 
0:96 147° 29’ | 92° 24’). 78° 20’) °922) 92,044 1°042 
0:94 140°. 6’ |» 89° 56'|.. 76° 24’ | +884 90,616 1:064 
0-92 138° 51" |} 87°: 32'| 74° 30’) +846 88,688 1:°087 
0:90 128° 19’ | 85°. 10’) 72° 36’ | +810 86,760 1-111 
0:88 123° V7" |. 82° 51. 70° 440 1 774 84,832 1°136 
0:86 118° 38’ | S0° 34’| 68° 54’ | »740 82,904 1/163 
0:84 1949319). 7 80° 2017. 672. 654-7106 80,976 1:190 
0:82 110° 10’.| 76° 8'| 65° 18’ | +672 79,048 1°220 
0-80 106° 16’ | 73° 58’| 63° 31’ | 640 77,120 1°250 
0:78 102° 31’ | 71° 49’; 61° 45’ | -608 75,192 1-282 
0:76 98° 56’ | 69° 42’| 60° 0’ | +578 73,264 1 316 
0°74 95° 28’ | 67° 36’) 58° 16’ | -548 71,336 1:351 
- 0°72 92°. -6’ | 65° 32’). 562 32' | *518 69,408 1-389 
0°70 88° 51’ | 63° 31’; 54°50’ |. 490 67,480 1-429" 
0°68 — 85° 41’ | 61° 30’, 53° 9! | +462) 65,552 1°471 
0°66 82° 36’ | 59° 30’, 51° 28 | -436, 63,624 1°515 
0-64 979° 35! | 579.31" 49° 48’ |} :410; 61,696 1°562_ 
- 0°62 760 38’ | 55° 34’| 48° 9° | +384! 59,768 | 1°613. 
0:60. 73° 44’ | 58° 38’| 46° 30’ 360 57,840 1°667 
0:58 70° 54’ | 51° 42’) 44° 51’ 336 55,912 1°724 
0°56 "68°. 6’ |. 49° 481). 43° 14° 314 53,984 1°786 
0°54 65° 22" |°47° 54") 419 37! 292 52,056 | 1°852 
0-52 62° 40’ | 46° 2’) 40° 0’ 270 50,128 1:923 
0°50 60° 0’ | 44° 10'| 38° 24’ 250 48,200 | 2-000 


‘Exawrie.—The apertures of four objectives, two of which are dry, one water-immersion, and one oil-immersion, 
‘would be compared on the angular aperture view as follows:—106° (air), 157° (air), 142° (water), 130° (oil). 
‘Their actual apertures are, however, 98 j "80 *98 1+26 1°38 or their 
|. numerical apertures. 
<1 eas 


( 


Be) 


Conversion of British and Metric Measures, 
1.) LInEAu 
Micromillimetres, §c., into Inches, §c. 


II. 
Scale showing || 
the relation of i : 
Millimetres, & poe 
&c., to Inches. |) 1 -000039 
| 2. +000079 
‘aud | 8 7000118 | 
com.” ins. | 4 -+000157 
5 -000197 
l= ™ 6 +000236 
les 7 -000276 | 
=a 8 000315 | 
[= | 9 -000354 | 
ft 10 *000394 | 
E | 11 +000433 
Ae 12 -000472 
=H 13 -000512 | 
[Es 14 -000551 | 
Hi 15. -000591 
jes 16 -000630 
ce a 17 -000669 
le z| 18 -000709 
=i 19 -000748 
E z| 20 +000787 
[Es 21 000827 
= 5| 22 -000866 
ae 28 -000906 
= el) 24 -000945 
Es 25 -000984 
Es 26 -001024 
=a 27 -001063 | 
Hy] | i ue 
=u 001142 | 
=5 30 -001181 | 
: | 81 -001220 
4 32 -001260 
[E | 83 *001299 
=m 84 -001339 
lz | 35 -001378 
= 36 "001417 | 
|e ® 37 ‘001457 | 
Es 39 -001535 
= w : : 
i F| 40 -001575 | 
ita 41 -001614 
lz | 42 -001654 
== 43 -001693 
[= :| 44 -001732. 
EE 45 -001772 
=n 46 01811 
[Ee 47 001850 | 
ee 48 -001890 
[ze 49 -001929 
= BS 60. -001969 | 
lz | 60 -002362 | 
zs 70 002756 | 
= 80 -003150 | 
(Ss 90. -003543 | 
= fl 100 -008937 | 
E z | 200 -007874 | 
=# | 800. 011811) 
[Es | 400 *015748 | 
os | 500 -019685 | 
| 600 023622 
1000'9 2 =) mms} ZOO | 027559 :| 
-.10mm=lem |) 800 +031496 | 
. 10cm, =1 dm, 900 _ +0354383 
10 dm. =1 metre.) LOOO (=1 mm.) 


3 
OWDIAMHPOwe F 


10 (icm.) - 


21 


1° 
I fod 
1: 
a 
1: 
I: 
1: 
x 
ye 
2 
1: 
i Ho 
reat 
1° 
1 
1 
1 
1 
I 
1 
1 
1 
1 
1 
T 


. 
. 
. 

. 
. 
. 
. 
. 


*039370 
"078741 
“118111 
"157482 
* 196852 
*236223 
*275993 
“314963 
"354334 


"433075 
*472445 
*511816 
*501186 
*590556 
*629927 
*669297 
*708668 
*748038 


ins. } 


393704. 


787409 


*826779 
*866150 
*905520 
“944890 
*984261 


023631 
063002 
102372 
141743 
181113 


220483 
259894 
299224 
338595 
377965 
417336 
456706 
496076 
535447 
974817 


614188 
653558 
692929 
732299. 
771669 
811040 
850410 
889781 
929151 | 


decim. 


3 


n> Bae 


6 


9 


2 
vee 
7 
8 


HT 


70 (7 em.) 


9 


9. 
-968522 | 100 (10 em.= 


. dns. 


3°9387043 
7874086 © 


11°811130 


15°748173 _ 


19°685216 
23622259 


27°559302 ~~ 
_81-496346 


RNNMNNMNNNHYY NNHPNNHNHNNNWNhD 


Fs 
2° 
De 
2: 
2° 
9- 
3: 
3: 
3: 
3: 


a 
3: 
3: 
8: 


59% 


3° 
3: 
3: 
3° 
8: 
3: 
3- 
3: 
3: 
‘3: 


Re 


3. 


3 


3: 


*559078 


*637819 
*677189 
*716560 
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ins, 


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“047262 
086633 
*126003 
“165374 
“204744 
“244115 
* 283485 
*322855 | 
*362226 | 


*401596 
"440967 


480337 
519708 


598449 


795301 
834671 
874042 
913412 
952782 
992153 
031523 
070894 


110264. 


149635 


189005. 


228375 
267746 
307116 
346487 
385897 
425228 


464598 | ~ 
508968. 


948339 


582709 | 
622080. | - 
661450 |. 
700820 | — 


740191 
779561 


818932 | - 

858302 |. 
897673 | 
ldecim.) |: 


55°433389 


- 3°280869 ft. 


1°093623 yda. 


10.(1 metre) 39°370482 9 


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Micromillimette: 
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( W ) | 3 


ITI. Corresponding Degrees in the 
Fahrenheit and Centigrade 


Scales. 
Fehr. Cent. Cent. Fabr. 
500 260° 0 100 212°0 
450 232-22 98 208°4 
400 204-44 96 204-8 
350 176° 67 94 201-2 
300 148-89 92 197-6 
250 121°11 90 194-0 
212 100-0 88 190°4 
210 98°89 86 186°8 
205 96-11 84 183-2 
200 93°33 82 179°6 
195 90-56 80 176°0 
190 87°78 78 172°4 
185 85°0 76 168-8 
180 82-22 74 165°2 
175 79°44 72 161°6 
170 76°67 70 158°0 
165 73°89 68 154-4 
160 71-11 66 150°8 
155 68°33 64 147°2 
150 65°56 62 143°6 
145 62°78 60 140-0 
140 60-0 58 136°4 
1385 57°22 56 132-8 
130 54-44 54 129-2 
125 51:67 52 125°6 
120 48°89 50 122-0 
115 46-11 48 118°4 
110 43°33 46 114°8 
105 40°56 44 111-2 
100 37°78 42 107°6 
95 35°0 40 104 0 
90 32-22 ' 38 100-4 
85 29-44 36 96°38 
80 26°67 34 93-2 
75 23°89 32 89-6 
70 21°11 30 86:0 
65 | 18°33 28 82° 
60 15-56 26 78 
55 12°78 24 75 
50 10-0 22 71 
45 7°22 20 68 
40 4:44 18 64- 
35 1-67 16 60- 
32 0-0 14 57° 
30 — I-11 12 53° 
25 =~ 3-89 10 50° 
20 — 6°67 8 46° 
15 — 9-44 6 42° 
10 — 12-22 4 39° 
5 — 15°0 > toe ip Ts 
0 —.17°78 8) 32° 
— 5 — 20°56} — 2 28° 
— 10 — 23:33 | — 4 24° 
— 15 — 26°11 | — 6 215 
— 20 — 23:89; = 8g eS 
— 25 — 31°67 | — 10 14: 
— 80 — 34°44 | - 12 10° 
— 85 — 37°22 | — 14 6° 
-— 40 — 40°0 — 16 3° 
— 45 — 42°78 | — 18 — 0 
-— 50 — 45°56 — — 4 


SHE OROANUDHROANUHKROTRNBDHROANAL 


| Diamond 
|. Phosphorus 


| Pure water 


IV. Refractive Indices, Dispersive 


Powers, and Polarizing 
Angles. Pare | 


(1.) Rernacrive xpices. 


ae 


Bisulphide of carbon 

Flint glass 

Crown glass 

Rock salt 

Canada balsam 

Linseed oil (sp. gr. -932) 

Oil of turpentine (sp. gr. *885) 
Alcohol 

Sea water 


Air (at 0° C. 760 mm.) 


' A a big pe . atk iad aby Op 


(2.) DIsPERSIVE PowERs, 


Diamond 
Phosphorus 
Bisulphide of carbon 
Flint glass 
Crown glass 
Rock salt 
Canada balsam 
Linseed oil (sp. gr. *932) 
Oil of turpentine (sp. gr. 885) 
Alcohol a 
Sea water 
Pure water bere PAN oe ei c® 
Air ee ee 
(3.) Potarizinae ANGLES 


Diamond 
Phosphorus 
Bisulphide ef carbon 
Flint glass 
Crown glass — 

Rock salt — 

Canada balsam ~ ie 
Linseed oil (sp .gr. -932) 


V. Table of Magnifying Powers. 


( il) 


- OBJEC- 


Beck's 2, 


1 Powell’s 1, and 
Ross’s A | Ross’s B, 
nearly.* 


MAGNIFYING Powrr. 


Beck’s 1, | Powell’s 2, 


5 | % | 10 


Be 
Powell's 3.| Ross's C. | Beck’s 3, | Powell’s 4, 


Qin. | 25 | lin. 


EYE-PIECES. 


ck’s 4, 


Beck’s 5 


Rises E. | Powell's 5. 


10 15 
123 183 
162 25 
25 3 
33h 50 
50 vis) 
623 932 
652 | 100 
215 1123 
100 150 
125 187} 
150 | 225 
1662 | 250 
200 300 
250 | - 375 
300 450 
350 525 
400 600 
450 675 
500 750 
550 825 
600 | 900 
650 | 975 
700 | 1050 
750 | 1125 
soo | 1200 
850 | 1275 
900 } 1350 
950 | 1425 
1000 | 1500 
1250 | 1875 
1500 | 2250 
2000 | 3000 
2500 4 3750 
-3000 j 4500 
4000 | 6000 


af “Teepectively yf, 


20 
25 


333 


50 - 


663 
100 
125 
1332 
150 
200 
250 
300 


3234 


400 


500 


less and ue more than the figures given in this column. 


* - Powell and Seaiurare No, 2= 7-4, and Beck’s No. 2 and Ross’s B= 8 magnifying power, or 


Ross’s F, 
Ro:-s’s D, 
FocaL LENGTH. 
Zin. | Sin. | Lin. | fin.) din. | din 
Maeniryine Power, 
} } ‘ 
| 1p | 1 20 | 2 20 | 40 
AMPLIFICATION OF OBJECTIVES AND EYE-PIECES 
- COMBINED. 
25 30 40 50 60 80 
312 374 50 623 15 100 
412 50 662 832 100 1331 
623 vb) 100 125 150 200 
831i 100 133: | 1662 200 2662 
125 150 200 250 300 400 
1563} 1873 250 312% 375 500 
1662 200 2662 3332 | 400 5332 
187} 925 300 375 450 600 
250 300 400 500 600 800 
312} 375 500° 625 750 1000 ~ 
375 450 600 750 900 1200 
4162 | 500 6662 8332 | 1000 13332 
500 600 800 1000 1200 1600 
+ 625 750 1000 1250 1500 2000 
750 960 1200 1500 1800 2400 
875- | 1050 } 1400 } 1750 2100 2800 
1000 1200 1600 } 2000 | 2400 3200 
1125 1350 1800 2250 2700 3600 
1250 | 1560 2600 2500 8000 4000 
1375 | 1650 | 2200 | 2750 3300 4400 
1500 1800 2400 3000 3600 | 4800 
1625 1950 2600 3250 3900 5200 
1750 2100 | 2800 } 3500 | 4200 | 3600 
1875 2250 | 3000 | 3750 4500 6000 
2000 2400 | 3200 | 4000 4800 | 6400 
2125 2550 | 3400 } 4250 5100 |- 6800 
2250 2700 | 3600 | 4500 | 5400 | 7200 
2375 2850 | 3800 4} 4750 5700 | 7600 
2500 | 3000 | 4000 | 5000 | 6000 | 8000 
- 8125 | 3750 | 5000 | 6250 | 7500 | 10009 
3750 4500 } 6000 | 7500 |. 9000 | 12000 
5000 | 6000 # 8000 {10000 | 12000 } 16000 | 
6250. | 7500 } 10000 | 12500 | 15000 } 20000 
7500 | 9000 } 12000 | 15000 | 18000 } 240v0 
10000 } 12000 | 16000 ¥e a 32000 


( 12) 


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First-Class Microscopes. 


Student’s Microscope. 


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_ VIL.—Note on the Spicules found in the Ambulaeral Tubes o 


JOURNAL 


OF THE 


ROYAL MICROSCOPICAL SOCIETY. 


TRANSACTIONS OF THE SOCIETY. 


———_—S= 


of th 
regular Echinoidea. By Professor F. Jerrrey Benn, M.A., 


F.R.MS. 
(Read 10h May, 1882.) 


Prats V. 


I wave thought that it might be of interest to the Society to have 
some further information on the feaeece of the spicules found 
in the ambulacral tubes of the regular Echmoidea. The greater 
part of our present knowledge on this subject we owe to the 
researches of one of our Secretaries, Mr. Charles Stewart, the 
most important of whose papers was published in the Linnean 
Society's ‘Transactions’ for 1865.* I have been emabled to 
examine a large series of genera and species, and as my leading 
object has been to find some further characters which would be of 
assistance in the classification of the groups and genera of the 
order, I have confined my attention at present to the sucking- 
tubes. 

Commencing with the genus Eehinus, I was struck by the 
constant presence in iis species of those C-shaped or bihamate 
spicules, the characters of which will be known to every microsco- 
pist (PL V. Fig. 1). Carrying on these researches further, I 


EXPLANATION OF PLATE V. 


Fie. 1.—Echinus (E. margaritaceus), to show the ordinary bihamate spicales. 
2.— Cottaldia (C. fortesiana). 

»  o&—FEchinocidaris (£. dufresnis). 

4.—FEchinothriz (2. turcarum). 

5.— Diadema (D. seiosumi). 

6.— Micropuga tuberculaia. 

7.— Asthenosoma pellucidum. 

8.—Phormosoma bursarium, 

9.—Salenia hastigera. 


* Vol. xxv. p. 365. 
Ser. 2.—Vot. I. xX 


298 Transactions of the Society. 


found that every genus of the so-called Triplechinide which I 
examined contained these same bodies; similarly they were to be 
found in the other division (T'emnopleuride) of the Echinide, as 
limited by Professor Alexander Agassiz. Nor were they here only ; 
when the suckers of the Echinometride were examined, the biha- 
mate spicules were again to be observed. In the Cidaride, 
Salenide, Echinothuride, Echinocidaride, and Diadematide, the 
bihamate spicules were, on the other hand, conspicuous by their 
absence ; and this being so, I found in their distribution among 
various genera of the Echinometride and Hchinide a gratifying 
support to the view on which I have elsewhere insisted, that 
these two groups differ less from one another than they do from 
any other group of the regular Echinoids. It may be worth while 
to give the names of the genera examined :—Heterocentrotus, Colo- 
bocentrotus, Echinometra, chinostrephus,* Strongylocentrotus, 
Spherechinus,* Pseudoboletia,* Temnopleurus, Salmacis, Mes- 
pila, Amblypneustes,* Microcyphus,* Cottaldia,* Echinus, Trip- 
neustes, Toxopneustes,* Hvechinus.* 

The number of genera examined is now sufficiently large to 
justify us in the belief that C-shaped spicules will always be found 
in the suckers of the Echinide, as I have proposed to define the 
term. 

With regard to the form here called Cottaldia, it may be added 
that the specimen was collected by the ‘Challenger, and that, 
therefore, it was determined by Prof. Alex. Agassiz; a reference to 
that naturalist’s report will sufficiently prove that he has had con- 
siderable difficulty in finding a place for the species; that difficulty 
cannot, however, extend to its general position, now that the 
spicules have been examined, and been found to be of the bihamate 
type (Fig. 2). 

With regard to the Diadematide, we have to note that, if the 
forms have been correctly united, there is not the same closeness in 
the characters of the ambulacral spicules in this group as there is 
in that of the Echinide ; though we can imagine a connection 
between the spicules of Echinothria (Fig. 4), and those of Diadema 
(Fig. 5) it hardly seems possible to associate with them those of 
Micropyga (Fig. 7) or of Astropyga, which have so striking a 
Holothurian facies, and no generalization can safely be made at 
present for this division. 

When Mr. Stewart published his paper in 1865 he had been 
unable to find spicules in the ambulacral tubes of Hchinocidaris 
(Arbacia). I, too, was for a time unable to find them, but at last 
they were detected; they are but scantily present, but are very 
characteristic, being greatly widened in the middle, and frequently 


t Proc. Zool. Soc. Lond., 1881, p. 418. 
* Those marked with an asterisk were not reported on by Mr. Stewart. 


Spicules in Ambulacral Tubes of Echinoidea. By Prof. Bell. 299 


perforated in that portion (Fig. 3). It would seem likely that the 
rarity of these spicules may be ascribed to the great thickness of 
the walls of the suckers, the development of muscular and con- 
nective tissue being so considerable that there is no such necessity 
for the spicules here as there igs in cases where the walls are 
thinner ; but the spicules themselves are proportionately large. 

The bihamate spicules of the HEchinide, the tri-radiate ones of 
Diadema, the flattened centrally enlarged form of Eehinocidaris, 
present little in common, and, while there would be no difficulty in 
distinguishing them, it is likewise impossible at present to make a 
suggestion as to how they might be derived from one another. 
When with these we compare the ambulacral spicules of Salenia it 
is not perphaps too hardy to suggest that in the irregular forms 
there to be found we may have something hardly more than 
“amorphous,” from which the forms of the later groups have been 
derived. 

There is no close resemblance between the spicules of Cidaris * 
and those of Phormosoma and Asthenosoma (Figs. 8 and 9); the 
reticular character of the spicules of the Echinothuride is doubtless 
to be associated with the comparative tenuity of their tests. 


* See Stewart, Quart. Journ. Micr. Sci, xi. (1871) pl. iv. 


Rew, 


500 Transactions of the Society. 


VIII.— The Relation of Aperture and Power in the Microscope.* 
By Professor Apps, Hon. F.R.MS. 
(Read 10th May, 1882.) 


I.— General Considerations as to Wide and Narrow Apertures. 


Tue question of the relative values of high and low apertures has 
been much obscured by the one-sidedness with which it has been 
treated. One party of microscopists—the “ wide-aperturists ”— 
having recognized that high apertures are capable of exhibiting 
minuter details than low apertures, conclude therefrom that all 
microscopical work must be done with very wide apertures, and 
that low-angled systems are worthless. Another party, relying 
upon the fact that there are many cases in which low or moderate 
apertures perform decidedly better than wide ones, generalize this 
experience and deny that there can be any essential benefit in very 
wide apertures, asserting that all observations, with the possible 
exception of resolving diatom striz, can be done as well with low- 
angled objectives. The premises of both these views may be said 
to be true, but true under conditions only ; and by disregarding 
these conditions both parties arrive at conclusions which are equally 
remote from a proper estimation of the requirements of scientific 
work with the Microscope. My view of the question f is based on 
the following considerations :—- 

1. Every given degree of minuteness of microscopic detail requires 
a given aperture in order to obtain a complete (or perfect) image, 
i.e. an image which is a true enlarged projection of the structure, 
exhibiting all elements in their true form and arrangement. ‘The 
minuter the dimensions of the elements the wider an aperture is 
necessary—the larger these dimensions the narrower an aperture 
is sufficient. Structures whose smallest elements are measured by 
considerable multiples of the wave-lengths of light are perfectly 
delineated with low or very moderate apertures, and their examina- 
tion with wide apertures does not improve their recognition. On 
the other hand, if we are dealing with objects whose dimensions (or 
structural elements) are equal to a few wave-lengths only, even the 

* The paper (received 8th April) is written by Professor Abbe in English. 

+ As some suggestion appears to have been made when the above paper 
was read as to my views having undergone a change, I beg to remind my readers 
that the views above explained are those which I have professed since 1873—the 
date of my first paper on the subject. My advocacy of wide apertures for 
minute objects appears to have been interpreted as an advocacy of wide apertures 
for all purposes—a misapprehension which I am at a loss to account for, as 
nothing I have ever said or written could justify any such a supposition. 

All the catalogues of Mr. Zeiss issued since 1872 give practical evidence of 
this, as the objectives tlere specified (and stated to be constructed according to my 


principles and under my direction) include no low and medium powers, except 
with low or very moderate apertures.—H, A. 


The Relation of Aperture and Power. By Prof. E. Abbe. 301 


widest apertures hitherto obtained will not afford complete or 
strictly true images, but will show these objects more or less 
incomplete or modified. ‘his general principle holds good in 
regard to objects of every kind, regular or irregular, isolated 
particles or composite structures, because the physical conditions of 
microscopical delineation are always the same. 

The obvious inference from this principle is that the widest 
possible apertures must be used for the observation of objects or 
structures of very minute dimensions, low and moderate apertures 
for relatively large objects. 

It may perhaps be said that the objects of microscopical research 
do not justify such a distinction of large and minute, since the 
works of nature are always elaborated to the minutest details, all 
coarse objects beg composed of smaller elements, and these of 
still smaller ones, &c. This is quite true in regard to the objects 
considered as uatural things, but not as objects of scientific 
research. The interest of research is not always directed to the 
ultimate elements, but is as often confined to the consideration of 
the coarser parts, and in such cases the observer is not only allowed 
but sometimes compelled, to disregard everything which is not con- 
nected with the scientific aim of his investigation. To observe 
every object in nature throughout, from alpha to omega, is the 
privilege of dilettante microscopy only, which has no distinct aim. 
There are many lines of the most valuable scientific research (e. g. 
the greatest part of all morphological investigations) which have 
not to deal with very minute things. This kind of work can be 
completely done with low or moderate apertures. 

‘Lo recommend the application of wide-angled objectives for 
every branch of microscopy, as has been, in fact, done by excited 
wide-aperturists, is no more to be supported than it would be to 
recommend the use of a magnifier to a painter for inspecting the 
tree which he proposes to delineate. 

According to what has just been said, the only benefit of 
greater aperture is that it is capable of delineating minuter things. 
Now minute dimensions require high amplifications in order that 
they may be enlarged to a visual angle suticient for distinct vision. 
Low figures of amplification cannot render visible (at least not 
distinctly visible) details which are beyond a certain limit of 
minuteness. Even if they are delineated by the Microscope they 
would remain hidden to the eye for want of sufficient visual angle. 
It follows theretore that wide apertures will not be utilized unless 
at the same time there is a linear amplification of the image, at 
least sufficient for exhibiting to the eye the smallest dimensions 
which are within the reach of such an aperture. On the other 
hand, a high amplification will be useless if we have small aper- 
tures which delineate details of dimensions only capable of being 


302 Transactions of the Society. 


distinctly seen in an image of much lower amplification. We have 
here an empty amplification, because there is nothing in the image 
which requires so much power for distinct recognition. In the 
first case (deficiency of power) the large aperture cannot show 
more than a smaller one ; in the other case (deficiency of aperture), 
the high amplification shows no more than a lower would do. 
Consequently :— 

Wide apertures when high amplification is required ; low 
or moderate apertures when low or moderate amplifications 
are sufficient or cannot be overstepped. 

2. The utilization of a given aperture depends in principle on 
the amplification of the ultimate image which is projected by the 
entire Microscope to the observer’s eye. Now one and the same 
amplification may be obtained in very different ways since it is the 
resultant of three distinct elements, (a) focal length of the objective, 
(b) focal length of the ocular, and (c) length of the tube. Any 
definite number of diameters (say 1000) can be obtained with a low 
power objective (say a 1-inch) as well, from a mere dioptrical 
point of view, as with a higher power (say 1-inch), by applying a 
sufficiently deep eye-piece and a sufficient length of the tube. It 
is, however, well known that there isa great difference in the optical 
qualities of images which are produced under these different con- 
ditions. Forcing a high amplification from a low-power objective 
is always connected with a considerable loss of sharpness of defi- 
nition of the image, owing to the magnification of the residuary 
aberrations, which are inherent even in the most finished construc- 
tions. It is, therefore, a well-established practical rule that a certain 
amount of amplification requires a certain power of the objective— 
higher amplification a higher power (shorter focal length)—in 
order to obtain the image under those favourable conditions which 
are necessary for their full effectiveness. This considered, the 
inference of the foregoing paragraph may be expressed in these 
terms :— 

Wide apertures with objectives of short focal length; low 
and moderate apertures with objectives of low and moderate 

ower. 

hae detailed discussion of this subject will be found in the 
second part of this paper, it will be sufficient here to point out 
some notable facts of experience by way of example only. 

With objectives of say 1 inch, and } inch, focal length, the lower 
and medium eye-pieces in use will yield 40-80 and 80-160 dia- 
meters only. In order to obtain 150 and 300 respectively, very 
deep oculars (or an extra length of the tube) would be required. 
So far now as such objectives are intended for the lower powers 
mentioned above, an aperture of about 0°15 (18°) in the case of 
the l-inch, and of 0:3 (85°) in the case of the 4-inch, are at all 


The Relation of Aperture and Power. By Prof. E. Abbe. 303 


events more than sufficient for showing every detail which can 
possibly be recognized by the eye under these amplifications, and 
therefore wider apertures are useless. In point of fact, no observer 
will see anything more or anything better with similar objectives 
of say 0:40 (48°) and 0°75 (96°) respectively, than with the 
narrower angles indicated above, as long as the low and medium 
oculars are in question only. These latter apertures would require 
for their full utilization, i.e. for convenient observation of the 
minuter details which are within their reach, amplifications of 
much more than 150 and 300 diameters. With well-made objectives 
of those apertures, such figures may be realized indeed, and details 
may be shown by means of deeper eye-pieces, which remain quite 
invisible with the lower angled systems; but no microscopist can 
deny the inferior quality of the images obtained in this way if 
compared to those of equal amplification, which are obtained with 
these same apertures when the objectives have double the power 
and the oculars the half only. Structures of so simple a com- 
position as diatom striz may perhaps be tolerably displayed under 
such forced amplifications of low-power objectives, but with objects 
of somewhat irregular and complicated structure the deterioration 
of the image attendant upon a considerable enlargement of the 
residuary spherical and chromatic aberrations by deep eye-pieces, 
becomes at once obvious even with the most finished objectives. In 
point of fact, no experienced histologist will ever use in ordinary 
work even an ocular amplification of the amount necessary for 
obtaining 100 diameters from a 1-inch objective or 200 from a 
3-inch. He would be unwise if he troubled himself with inferior 
images whilst good images of the amplifications required could be 
obtained with equal, or even greater, convenience with objectives of 
the same apertures but half the focal length. 

The above is an example of waste of aperture, or lack of useful 
power ; waste of power and lack of aperture are exemplified by every 
objective of excessively short focal length, e.g. 4, mch. Such a 
lens, even if immersion, cannot be made with an aperture of much 
greater numerical value than 1-0, in consequence of the technical 
obstacles arising with such very short focal lengths. Now the limit 
of an aperture of that amount is entirely exhausted, at all events 
with a power of 1000 to 1200 diameters, inasmuch as nothing of 
the real attributes of an object can be seen with that aperture under 
a higher amplification, which could not be as well recognized under 
the lower. A 3,, however, will yield 1500-2000 diameters with 
the lowest eye-pieces which are usually employed. The lowest 
attainable power is therefore an empty power already, and every 
useful amplification available with the aperture in question could be 
obtained under favourable conditions and with much less inconye- 
nience by an objective of half the power, or even less. 


304 Transactions of the Society. 


3. The preceding shows that wide apertures can only be 
utilized in the observation of minute details, under high amplifica- 
tions obtained with objectives of short focal length. Wide aper- 
tures are therefore useless when those conditions are not fulfilled, 
because in this case the same result could be obtained as well 
with low-angled systems. But as abundance prima facie is 
no detriment, the foregoing considerations do not enforce any 
positive objection to the use of wide apertures for every kind 
of work. ‘There are however other points of view from which 
it becomes obvious that the application of wider apertures than 
can be utilized is not merely superfluous but is a decided disad- 
vantage, inasmuch as they prevent the utilization of some really 
valuable benefits which are the privilege of low and moderate 
apertures. 

The first disadvantage results from the reduction of the depth 
of vision (or the “penetration” of the Microscope) which is 
connected with wide apertures. I have given in another place* 
a discussion of the circumstances on which penetration depends, 
and the formule which afford an approximate numerical estimation 
of the depth of vision in microscopic observation. These theoretical 
suggestions show (in accordance with the experience of practical 
microscopists) the reduction of penetration with increasing aperture 
under one and the same amplification, and especially when the 
amplification is not restricted to very small figures. Now there 
are many objects of microscopical research which do not require, 
and, indeed, do not even admit of high powers, but demand for 
effective investigation as much penetration as possible. This is 
always the case where the recognition of solid forms is of import- 
ance, and therefore a distinct (at least, a tolerably distinct) vision 
of different planes at once must be possible, whether the observa- 
tion is assisted by stereoscopic devices or not. The greater part 
of all morphological work is of such a kind, and in this line of 
observation therefore a proper economy of aperture is of equal 
importance with economy of power. 

Whenever the depth of the object under observation is not 
very restricted, and it 1s essential that the depth dimension shall 
be within the reach of direct observation, low and moderate powers 
cannot be overstepped, and no greater aperture should therefore be 
used than is required for the effectiveness of these powers—an 
excess in such a case is a real damage. High powers and corre- 
spondingly wide apertures are restricted to those observations 
which do not require any perceptible depth of vision, i.e. to two 
different cases (1) when the objects are quite flat or exceedingly 
thin; (2) when preparations of greater depth are sufficiently trans- 
parent to admit of an ¢ndirect recognition of their solid structure 

* See this Journal, i. (1881) p. 689. 


The Relation of Aperture and Power. By Prof. E. Abbe. 305 


by means of successive optical sections through successive focus- 
sing of different planes. For the latter method of observation the 
loss of penetration with increasing power and aperture is no draw- 
back, but rather an advantage, because it enhances the distinct 
separation of the sectional images at successive foci. A disregard 
of these natural restrictions in the use of wide apertures is 
obviously the origin of the opinion that aperture per se is antago- 
nistic to good definition. It is quite true that there are many 
even very delicate objects which are much better seen under a 
given amplification with a system of very moderate than with one 
of very wide aperture, the former giving a clear view of the 
whole structure, the latter showing perhaps some distinct points, 
but as a whole veiled in haze. Provided, of course, that we have 
well-corrected objectives, the fault here is not on the part of the 
lens, but on the side of the object, which requires for proper 
recognition a greater range of depth than is reconcilable with a 
wide aperture. The theoretical suggestion which has been brought 
forward in support of the notion that different parts of the clear 
area of an objective produce dissimilar images, and that therefore 
the resultant image must show increasing confusion with increasing 
aperture, cannot apply to the delineation of a plane object. In a 
well-corrected objective the partial pictures received through the 
various parts of the aperture-area are-always strictly similar so far 
as one plane of the object is concerned. ‘he confusion suggested 
is nothing else but confusion of the images of different depths— 
lack of penetration, but not lack of “ definition” m any reasonable 
sense of that term. Provided the objectives are properly corrected 
and the objects are fit for the delineation of an image, undisturbed 
by interfermg confused images from other planes, the “ defining 
power” of an objective is always greater with greater aperture for 
every kind of objects, inasmuch as under all circumstances the wider 
aperture admits of the utilization of higher amplifications than 
can be obtained without perceptible loss of sharpness (with the 
same objects) by lower apertures. 

There is therefore no drawback in principle to the use of a 
large aperture when the objects are suitable. But the considera- 
tions above lead to the conclusion :— 

Wide apertures (together with high powers) for those 
preparations only which do not require perceptible depth of 
vision, t.e. for exceedingly flat or thin objects, and for trans- 
parent objects which can be studied by optical sections. 
Moderate and low apertures when a wide range of pene- 
tration cannot be dispensed with. 

4. There is still another point of view, and one of special 
practical importance, which shows the positive damage connected 
with the use of wnnecessarily wide apertures. The increase of 


306 Transactions of the Society. 


aperturé is prejudicial to the ease and convenience of microscopical 
work in two essential respects. 

Istly, It necessitates a progressive reduction of the working 
distance of the objective. Owing to the rapid increase of the 
anterior aberration with increasing obliquity of the marginal rays 
(particularly in the case of dry lenses), perfect correction of a 
system cannot be obtained unless the layer of low refraction 
between the object and the front lens (i.e. the working distance) 
is reduced to a certain fraction of the focal length of the system, 
which fraction is necessarily diminished in a rapid proportion as 
the aperture becomes greater and greater. Whilst there is no 
objection to retaining as working distance 1%, of the focal length 
for an aperture of 30°, if the aperture is 60° not more than 53, 
can be allowed, and with an aperture of 116° really good correction 
is not reconcilable with a working distance exceeding 74 of the 
focal length. It is therefore an obvious disadvantage to use 
aperture angles of 60° and of 116°, when the power which is 
required or available can be obtained with 30° and 60° respec- 
tively. 

2ndly, Increase of aperture is inseparable from a rapid increase 
of sensibility of the objectives for slight deviations from the con- 
ditions of perfect correction. The state of correction of an objective 
depends on the thickness of the refracting film between the radiant 
and the front lens, represented by the cover-glass and that por- 
tion of the preparation which is above the actual focus. This is 
a variable element independent of the objective itself. In order 
to avoid large aberrations which must result from the change of 
that element, its variation must either be confined to narrow limits 
or must be compensated for by a corresponding change in the 
objective. Now there is a great difference in regard to this 
requirement between the objectives of low and of wide aperture, 
in particular with the dry system. An objective of a few degrees 
is almost insensible, it may be focussed to the bottom of a trough 
of water without any loss of performance. With 30° differences 
in the cover-glasses within the usual limits are still inappreciable, 
and an object may be seen at the depth of a drop hanging on the 
under surface of a cover-glass. With 60° a deviation of the cover- 
glass from its standard thickness by not more than 0°1 mm., or a 
corresponding increase of the depth of the preparation above the 
actual focus, will introduce perceptible aberrations and a visible loss 
of definition if not compensated for. With an aperture exceeding 
100° in a dry lens, the same result will arise from a change of 
thickness of 0:02 mm. only. To preserve always the best cor- 
rection in such a system would necessitate a change of the 
correction-collar for almost every change of focus in the inspec- 


The Relation of Aperture and Power. By Prof. E. Abbe. 307 


tion of successive layers, unless the preparation is exceedingly 
thin.* 

So far as the necessity of obtaining a certain amount of amplifi- 
cation in an efficacious manner requires a certain aperture, the 
above-mentioned restrictions and difficulties in the proper manage- 
ment of the objectives cannot be avoided. But all restrictions in 
regard to the objects, and all the trouble taken in the adjustment 
of the objectives, is quite for nothing when the same result can be 
obtained with a lower aperture. If for the sake of convenience the 
precautions required in the use of wide-angled lenses should be 
disregarded in working with the lower powers of wide aperture, 
the performance of such lenses is always worse than that of much 
narrower apertures under the same amplification. The best wide- 
angled system, if not carefully adjusted when in use, is not better 
than a bad low-angled lens, for the tolerably sharp image, which 
could be still obtained through the central part of the aperture 
alone (even under the imperfect state of correction) is disturbed 
by the coarse dissipation of light from the ineffective marginal parts 
of the aperture. 

The amateur who likes the Microscope for his amusement may 
not much object to some extra trouble connected with the use of 


* The reduction of this sensibility in somewhat large apertures is one of the 
great practical advantages of the immersion-method. ‘The extreme increase of 
that sensibility which is met with when the aperture of dry lenses approaches 
the maximal value of a for air (1 N.A.), is in my opinion a strong objection to 
the construction of such lenses with greater apertures than 0°80-0°85. Not only 
in this case must the working distance be reduced to an intolerably small 
amount in order to obtain proper correction, but the preservation of that correction 
in the practical use of the systems is almost impossible, notwithstanding the 
correction-collar, whilst at all events the very slight benefit of optical performance 
is not worth speaking of in comparison to the large increase obtained with the 
immersion-method under so much more favourable conditions. 

I need scarcely point out here that the claim of a special insensibility of 
certain lenses in regard to differences of the cover-glass (as has been sometimes 
made) is, to say the least, either great thoughtlessness or simple self-delusion, 
just as are similar claims of special penetration in favour of certain objectives. 
The aberrations in question, as well as the dissipation-circles from difference of 
focus, originate outside the Microscope, The particular construction of the 
objective cannot possibly therefore influence their amount in a cone of rays of 
given aperture, and the degree in which both become visible in the ultimate image 
of the Microscope must be strictly determined by the same elements which 
determine the visibility of any real object of given dimensions at the same plane 
of focus. There is no room left, therefore, for special properties of different 
constructions. 

» It is, however, true that an apparent insensibility, as well as an apparent 
depth of focus, is sometimes found, viz. in badly corrected objectives. When a 
system has no distinct focus at all, it is quite evident that the dissipation-circles 
arising from different thicknesses of the cover-glass, and from the difference of 
focus of different levels, may become much greater before the deterioration of the 
indistinct image becomes visible. Well-corrected objectives must be sensitive in 
both respects in strict accordance with their aperture so far as one and the same 
system of construction (dry or immersion) is in question. 


308 Transactions of the Society. 


wide-angled low-power lenses, which he admires as_ brilliant 
specimens of optical art. For those, however, who work with the 
Microscope, the economy of labour to which they are obliged will 
be expressed by the rule :— 

Never use wider apertures than are necessary for the 
effectiveness of the power, because excess of aperture is 
always waste of time and labour. 

5. A few remarks about another point of practical interest. 
By those who plead in favour of large apertures 2n all cases, it has 
been sometimes suggested as a rational plan for reconciling opposite 
demands, to have all objectives constructed with relatively wide 
angles, and to reduce them by stops or diaphragms when smaller 
angles are desired. The greater penetration and insensibility of 
the low apertures may of course be attained thereby: but never- 
theless this device is only a makeshift; and the result is inferior to 
that obtained by objectives originally arranged for a lower aperture. 
It is not merely that the stops cannot increase the working 
distance (which will always remain at the point corresponding 
to the full aperture of the lens), but that the low-angled lens 
which is made out of a good wide-angled one by means of a stop, 
is in optical respects a relatively bad objective—not nearly as well 
corrected as the same power would be if carefully adjusted for the 
lower angle. The reason will be readily understood from the 
following consideration. 

The best correction of an objective of given aperture depends 
on the proper distribution of a certain amount of residuary aberra- 
tion, which cannot be eliminated with our present means. ‘The 
greater the aperture the more aberration must be intentionally left 
at the central part of the system in order to prevent an obnoxious 
accumulation in the marginal zone. It is obvious, therefore, that 
with an aperture-angle of say 90° the inmost cone of 45° cannot 
be so well corrected as it might be if the marginal zone could be 
left out of account. ‘The effect is by no means inconsiderable, 
particularly in regard to the colour corrections. Owing to the 
chromatic difference of the spherical aberration the central portion 
of a somewhat wide aperture must always, even in a well-arranged 
objective, be perceptibly under-corrected chromatically, and in 
using this central part alone (the compensating influence of the 
over-corrected marginal zone being done away with), we have the 
performance of an inferior lens. In point of fact, no intelligent 
optician would ever make an objective of 30° aperture on the 
same formula as one of 60°, or one of 60° on the same formula as 
another of 100°, though this could be done by merely reducing 
the clear diameter of the lenses. 

There cannot, therefore, be a reconciliation between the pleasure 
of exhibiting mere optical accomplishment and the interests of the 


The Relation of Aperture and Power. By Prof. E. Abbe. 309 


working microscopist. Bad lenses will certainly not meet the 
demand for low and medium powers affording the utmost possible 
economy of time and labour in scientific work. This can be done 
only by systems in which all advantages attendant upon the lower 
apertures are fully realized by constructions specially aiming at 
the best which can be obtained under the actual conditions of the 
case. 

The progressive increase of aperture in the higher powers, for- 
merly within the capabilities of the dry system, and at a later period 
by the development of the immersion method, is, without any reason- 
able doubt, the most important feature of the modern advance of 
microscopical optics. It has rendered possible the successful ex- 
tension of microscopical research to minuter and minuter objects, 
which otherwise would have been impossible by the ineffectiveness 
of all increase of amplification beyond certain low figures. The 
appreciation of that progress and the recognition of its true basis 
has led to a tendency to increase more and more the aperture of 
every kind of objectives. The fact has been disregarded that it is 
an entirely different thing whether the object is to promote 
the performance of the Microscope in the whole at the limits of its 
power, or to promote its performance for aims beyond these limits. 
The opinion has thus arisen that what is a benefit for one kind of 
lenses must also be a benefit for every other kind. Objectives of 
low and medium powers (1-inch to }-inch) of 15° to 60° are pro- 
claimed at this time by many microscopists as old-fashioned and 
worthless things; 45° to 100°, or even 60° to 140°, are wanted 
for the same powers. Now as from a purely technical point of 
view, if 2s an accomplishment when the delineating power of an 
objective cannot be exhausted even with the deepest eye-pieces, 
opticians (notwithstanding the total bootlessness of such a super- 
abundance) of course take pleasure in making such “superior” 
lenses, and the natural consequence is that the lower apertures 
required for useful scientific research are likely to be esteemed as 
second-rate work, no longer worthy of high technical art. 

This opinion is a fatal mistake, and its practical effect, if not 
counteracted, will be a decided retrogradation of microscopical 
optics. Nobody, of course, can have the least objection to the 
construction of lenses of any descripition whatever for the personal 
pleasure of this or that microscopist. Strong opposition should, 
however, be made against all tendencies of captivating microscopical 
optics, in favour of such predilections, at the cost of the general 
usefulness of the instrument. 

Scientific work with the Microscope will always require not 
only high-power objectives of the widest attainable apertures, 
but also carefully finished lower powers of small and very 
moderate apertures. 


310 Transactions of the Society. 


IX.—The Bacteria of Davaine’s Septicemia. 
By G. F. Dowprswett, M.A., F.R.MS., F.CS., &. 
(Read 10th May, 1882.) 


THE organisms here shown under the Microscope, and which occur 
in the blood of the rabbit. in the form of septicaemia known as 
that of Davaine (one of the first who described it, about twenty 
years ago), are remarkable, in many respects, from a microscopical 
point of view, and possess a general interest from their relation to 
the affection in which they occur, and which has been regarded 
almost as the type of a specific parasitical disease, from the cireum- 
stance that the blood of an animal in these cases is infective in 
inconceivably small quantities. The statements of Davaine on this 
point, which attracted so much attention, were that the trillionth,* 
or the ten-trillionth part of a drop of this blood was infective. 

His experiments were repeated by several observers, who con- 
firmed his results in different degrees. I have myself found, in 
numerous experiments, that in the case of rabbits the blood is 
usually infective up to the millionth and the hundred-millionth 
part of a drop; sometimes in even smaller quantities, obtained by 
successive dilutions. 

In such blood I have found that the organisms here described 
always occur, but in very variable numbers; in some cases not 
more than one or two are to be found in each field of view, in 
others they exceed many times the number of the blood-corpuscles ; 
they do not appear to increase in any marked manner shortly after 
death, as is the case in some other affections. The microphyte itself 
is a form of Bacteriwm, in the generic sense of the term, as defined 
by Cohn ; its diameter, which varies less than that of any other form 
of Schizophyte which I have examined, is just over half a micro- 
millimetre (0°509 y), almost exactly 5455 m. The length which, 
in different stages of development, is very variable, may be put 
down at from 13 to 2, 3, or, in a few cases, 5 times the diameter, 
that is, of the single cells, or rods as they are commonly termed ; 
two or three of these, but not more, sometimes occur united together, 
endwise, forming short chains; but they never, in the blood of an 
animal, form either long leptothrix filaments or zoogloea masses. 
They frequently appear in the form of a figure of 8, or a dumb- 
bell ; this, as is shown in stained preparations—an example of which 
may be seen in the field of view under the Microscope—is not due 
to a constriction of the cell-wall, indicating incipient fission, but to a 
difference in its constituent parts and their refractive power ; the 


* A trillion in the French notation is a billion in the English, i.e. a million 
squared, 


Bacteria of Davaine’s Septicemia. By G. F. Dowdeswell. 311 


two ends are the most highly refracting, they take the staining 
more deeply than the intermediate portion, which is often with 
difficulty perceptible ; the ends thus stained present the appearance 
of forming spores, in some cases so distinctly that I am disposed to 
think this is really the case, though I have never witnessed their 
complete development. 

The preparation shown is from the blood of a rabbit of the 
third generation of artificial infection, it was made very shortly 
after death, and treated by the methods introduced by Weigert and 
Koch, which have been described elsewhere, and are now pretty 
generally known and adopted. I have not found these Bacteria in 
any of the organs or the tissues, excepting the blood and the lymph 
of an infected animal, examined immediately after death, not even 
in the lungs or the spleen, where, judging from other cases, we 
should expect to meet with them; their minute size, however, 
and more especially their not readily staining, would render them 
very difficult to distinguish in the tissues. In the blood this 
Bacterium is evidently motile, sometimes very actively so. 

Notwithstanding the interest and attention which this affection 
has excited during several years, and the importance of the micro- 
phyte in relation to the question of the true nature of the contagium, 
it has not, I believe, been figured or at all carefully described by 
any one, excepting only by Coze and Feltz, in a work published at 
Strasbourg and Paris several years ago; their description is im- 
perfect, and does not in any way coincide with my own observa- 
tions; they even give the diameter of the organism just three 
times as great as I have found it. These measurements I have 
checked by the use of the admirable standard stage micrometer 
recently constructed by Professor Rogers, of Cambridge, U.S.A., 
one of which I have received, and which is most valuable in 
enabling different observers to compare exactly their measurements. 
The immense discrepancy, however, between my observations and 
those of Coze and Feltz, cannot be reconciled by any variations in 
the standard scale used, and renders it difficult to believe that the 
same organism has been observed in the two cases. This opens up 
a very important, indeed a fundamental question with reference to 
the etiology of this affection, which need not be discussed here; I 
will only say that in the course of very numerous experiments, in 
different series, I have found the organism specifically distinct, 
invariable and constant in all cases, thereby conforming to the 
first and most important condition which has been laid down as a 
test for a specific parasitical contagium. 

In relation to the dimensions of the organism, and the infective 
virulence of the blood in which they are contained, a very curious 
question arises as to how many Bacteria or their germs can be 
contained in-a given quantity of blood, and this, as far as I know, 


312 Transactions of the Society. 


has never been yet considered or referred to. Taking the dimen- 
sions of the Bacteria to be, diameter 0°5 yw, which is a fraction less 
than the actual measurement, and the length to be 2 diameters, 
which is undoubtedly under the average, a very simple calculation 
shows that in a drop, taken as the 16th part of a cubic centimetre, 
there would be 250,000,000,000 (two hundred and fifty thousand 
million), or just a quarter of a billion; this would be when the 
blood was entirely filled with, or rather replaced by a solid mass of 
Bacteria, leaving no space at all for the blood-corpuscles and but 
little for the plasma; and this is the utmost number which a drop 
cculd contain. I think it is evident, therefore, that there is some 
fundamental error in Davaine’s statement and in that of those who 
have followed him, on this point. I have endeavoured directly to 
enumerate the number of Bacteria present in different portions of 
blood, but I cannot pretend to have succeeded with even approxi- 
mate accuracy ; the greatest number I could enumerate or estimate 
was a few millions in a drop. 

Another point of special interest in this affection is the asserted 
increase in the infective virulence of septiczemic blood in successive 
generations of transmitted infection. This theory was explicitly 
maintained by Coze and Feltz, but Davaine’s statements on the 
subject have been somewhat misunderstood, for although he asserted 
this in the fullest extent at first, he ultimately qualified the state- 
ment in some measure by showing that the maximum of viru- 
lence is reached very early; subsequent observers overlooked this 
qualification, and repeated and even improved upon Davaine’s 
original statements. This question has again lately attracted 
attention in connection with the relation of micro-organisms to 
disease, and the sensational and, were they to be credited, appalling 
statements that have been made, and even supported, by high 
authority, asserting a transformation of physiological species in 
some of the lower organisms, which hypothesis, it was supposed, 
might be connected with or account for an increase in infective 
virulence in the organisms present in septiceemic blood in successive 
generations. On this point I shall only say that I have found in 
a long series of experiments recently made, that although the 
infectivity of such blood may be slightly variable, there is no such 
thing as progressive increase of virulence in successive generations ; 
the blood of the first generation is actively infective in the millionth 
or the 100-millionth of a drop, or less, and it is not, and indeed 
for the reasons already stated, cannot be infective in very much 
smaller quantities, in the 25th nor any succeeding generations, 
nor is there any shortening of the incubation period, which in the 
large majority of cases is remarkably constant, ranging from 
twenty-one to twenty-four hours. 

The relation of the organisms here described to the disease in 


The Bacteria of Septicemia. By G. F. Dowdeswell. 313 


which they occur, has recently been the subject of experiment in 
Germany ; I shall only say with regard to this that on investi- 
gating this question, it appears to me clear that the Bacterium 
does constitute the specific virus, the actual contagium of the 
affection. 

The importance of the relations of these microphytes to disease, 
and indeed their role in the whole economy of nature is now so 
generally acknowledged that it is unnecessary to dwell upon it. 
It is only quite recently that the subject has been systematically 
developed, and already most valuable results have been attained, 
some of which, in regard to a most important practical application, 
viz. to tubercular disease, have only been communicated during the 
last month, and demonstrated in this College in the present week. 
It is by the microscopical examination of the organisms and the 
determination of their specific morphological characters alone, that 
many of the most weighty questions which present themselves can 
be determined. There is no field of microscopical research which 
requires more care or better optical appliances than these organisms, 
and none more worthy the attention of microscopists. 


Ser. 2.—Vot. II. v 


314 SUMMARY OF CURRENT RESEARCHES RELATING TO 


SUMMARY 


OF CURRENT RESEARCHES RELATING TO 


ZOOLOGY AND BOTA 


(principally Invertebrata and Cryptogumia), 


MICROSCOPY, &c., 


INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS* 


ZOOLOGY. 


A. GENERAL, including Embryology and Histology 
of the Vertebrata. 


Germinal Layers of the Chick.j—Professor F. M. Balfour and 
Mr. F. Deighton record the results of a renewed study of two much 
disputed points in the ontogeny of birds, viz. the origin of the 
mesoblast and the origin of the notochord. 

1. With reference to the first of these, their results are briefly as 
follows :— 

The first part of the mesoblast to be formed is that which 
arises in connection with the primitive streak. This part is in the 
main formed by a proliferation from an axial strip of the epiblast 
along the line of the primitive streak, but in part from a simul- 
taneous differentiation of hypoblast cells also along the axial line of 
the primitive streak. The two parts of the mesoblast so formed 
become subsequently undistinguishable. The second part of the 
mesoblast so formed is that which gives rise to the lateral plates 
of mesoblast of the head and trunk of the embryo. This part 
appears as two plates—one on each side of the middle line—which 
arise by direct differentiation from the hypoblast in front of the 
primitive streak. They are continuous behind with the lateral wings 
of mesoblast which grow out from the primitive streak, and on their 
inner side are also at first continuous with the cells which form the 
notochord. 

In addition to the parts of mesoblast, formed as just described, 
the mesoblast of the vascular area is in a large measure developed 
by a direct formation of cells round the nuclei of the germinal 
wall. 

The mesoblast formed in connection with the primitive streak 

* The Society are not to be considered responsible for the views of the 
authors of the papers referred to, nor for the manner in which those views 
may be expressed, the main object of this part of the Journal being to present a 
summary of the papers as actually published, so as to provide the Fellows with 
a guide to the additions made from time to time to the Library. Objections and 
corrections should therefore, for the most part, be addressed to the authors. 
(The Society are not intended to be denoted by the editorial ‘‘ we.” 

t+ Quart. Journ. Mier, Sci., xxii, (1882) pp. 176-88 (3 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. wED 


gives rise in part to the mesoblast of the allantois, and ventral part 
of the tail of the embryo, and in part to the vascular structures 
found in the area pellucida. 

With reference to the formation of the mesoblast of the primitive 
streak, the authors’ conclusions are practically in harmony with 
those of Koller; except that Koller is inclined to minimize the share 
taken by the hypoblast in the formation of the mesoblast of the 
primitive streak. 

Gerlach, with reference to the formation of this part of the meso- 

iast, adopts the now generally accepted view of Kdlliker, according 
to which the whole of the mesoblast of the primitive streak is 
derived from the epiblast. 

As to the derivation of the lateral plates of mesoblast of the 
trunk from the hypoblast of the anterior part of the primitive streak, 
the authors’ general result is in complete harmony with Gerlach’s 
results, although in their accounts of the details of the process they 
differ in some not unimportant particulars. 

2. As to the origin of the notochord, their main result is that 
this structure is formed as an actual thickening of the primitive 
hypoblast of the anterior part of the area pellucida. It unites 
posteriorly with a forward growth of the axial tissue of the primitive 
streak, while it is laterally continuous at first, both with the meso- 
blast of the lateral plates and with the hypoblast. Ata later period 
its connection with the mesoblast is severed, while the hypoblast 
becomes differentiated as a continuous layer below it. 

As to the hypoblastic origin of the notochord, they are again in 
complete accord with Gerlach, but differ from him in admitting that 
the notochord is continuous posteriorly with the axial tissue of the 
primitive streak, and also at first continuous with the lateral plates 
of mesoblast. 

The authors add :— The account we have given of the forma- 
tion of the mesoblast may appear to the reader somewhat fantastic, 
and on that account not very credible. We believe, however, that if 
the view which has been elsewhere urged by one of us, that the 
primitive streak is the homologue of the blastopore of the lower ver- 
tebrates, is accepted, the features we have described receive an 
adequate explanation. 

“The growth outwards of part of the mesoblast from the axial 
line of the primitive streak is a repetition of the well-known growth 
from the lips of the blastopore. It might have been anticipated that 
all the layers would fuse along the line of the primitive streak, and 
that the hypoblast as well as part of the mesoblast would grow out 
from it. There is, however, clearly a precocious formation of the 
hypoblast ; but the formation of the mesoblast of the primitive streak, 
partly from the epiblast and partly from the hypoblast, is satisfactorily 
explained by regarding the whole structure as the blastopore. The 
two parts of the mesoblast subsequently become indistinguishable, 
and their difference in origin is, on the above view, to be regarded 
as simply due to a difference of position, and not as having a deeper 
significance. 

yx 2 


316 SUMMARY OF CURRENT RESEARCHES RELATING TO 


“The differentiation of the later plates of mesoblast of the trunk 
directly from the hypoblast is again a fundamental feature of verte- 
brate embryology, occurring in all types from Amphioxus upwards, 
the meaning of which has been fully dealt with in the ‘ Treatise on 
Comparative Embryology’ by one of us. Lastly, the formation of 
the notochord from the hypoblast is the typical vertebrate mode of 
formation of this organ, while the fusion of the layers at the front 
end of the primitive streak is the universal fusion of the layers at 
the dorsal lip of the blastopore, which is so well known in the lower 
vertebrate types.” 


Development of Lepidosteus.*—Prof. F. M. Balfour and Mr. W.N. 
Parker state that the ovum is invested by a thick inner membrane, 
and an outer layer of pyriform bodies, which would seem to be metamor- 
phosed follicular epithelial cells; the segmentation is complete, though 
very unequal; here, as in the division of the epiblast into an epidermic 
and a nervous stratum, and in the formation of the walls of the 
brain, &c., from a solid “ medullary keel,’ we have resemblance to the 
Teleostei; the same is true of the archinephric duct, which is developed 
from a hollow ridge of the somatic mesoblast, and, by constriction, 
gives rise to a duct with an anterior pore, leading into the body-cavity. 
The olfactory sacs arise as invaginations of the nervous layer of the 
epiblast, the superficial epidermic layer becoming ruptured to allow 
of communication with the exterior; the primitive single opening 
divides to give rise to the double opening of the adult. The suctorial 
disk of the larva is shown to be formed of papillee composed of 
elongated epidermic cells, which probably pour out a viscid secretion. 
“The pronephric chambers remain in communication with the body- 
cavity by two richly ciliated canals; some of the mesonephric tubes 
of the larva have peritoneal funnels. No traces of a hyoid gill were 
detected in any larve. 


Spermatogenesis in Vertebrates and Annelids.j—A. Sabatier 
considers that the observations he has made on spermatogenesis in 
Salmacina, one of the Serpulide, throw great light on the process in 
Vertebrates. 

The spermatospores, or mother-cells, which line the walls of the 
spermatic sacs, are, by multiplication of the nuclei and by budding, 
covered with claviform pedunculated cells, the protospermoblasts. 
Each of these enlarge, detac!i themselves from the group, and in their 
turn present a new multiplication of nuclei with superficial budding. 
Hence arises a second generation of spermatoblasts, the deutospermo- 
blasts, which are ultimately transformed into spermatozoids, the nuclei 
of the former forming the heads of the latter, while the body and tail 
are filaments of the protoplasm. 

This double generation appears to the author to explain, simply 
and rationally, the complicated and very extraordinary process attri- 
buted by Balbiani to the process of spermatogenesis in vertebrates. 
The cellular groups composed of a large round central cell (female 


* Proc. Roy. Soc., xxxiii. (1881) pp. 112-9. 
t+ Comptes Rendus, xciy. (1882) pp. 172-3. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 317 


element), and small peripheral smooth cells applied to their surface 
(male element), which he considered to be primordial ovules sur- 
rounded with epithelial cells, and consequently as young male 
Graafian follicles, are the primitive spermatospore covered with the 
protospermoblasts, and the group of daughter-cells, which, according 
to Balbiani, are produced by budding of the epithelial cells, are in 
fact the deutospermoblasts. 

There is therefore no necessity to imagine the intervention of a 
conjugation of elements of supposed different sexuality, and a fecunda- 
tion of which there is no serious proof. 

Further researches on the Plagiostomi (Raja and Scyllium) and 
Amphibia (Rana, Hyla, and Bufo), have confirmed the author's views. 
He is also satisfied that the oval refracting bodies observed on the sides 
of the bundles of spermatozoids before maturity (the “ problematical 
bodies” of Semper to which Balbiani attributed a very important 
function as the female fecundating element) are simply nuclei of 
deutospermoblasts which have not undergone division. 


Cell-structure.*—The first portion of W. Flemming’s third con- 
tribution to this subject deals with the ovum of the Echinodermata. 
He finds that in the ripe ovarian ovum of the Hchinoidea (and it may 
be supposed in others also), there is a radiate arrangement of the 
protoplasm of the eggs, which persists and even becomes more distinct 
during fertilization ; this radiation is not to be confused with the 
formation of the asters. There exists a sperm-nucleus which fuses 
with the ovarian nucleus ; the sperm-nucleus is formed by the anterior 
portion of the head of the spermatozoon, or that part to which 
Flemming gives the name of the chromatic substance. The doctrine 
of Fol, that the protoplasm of the male element alone enters into 
union, cannot be held; what is rather true is that the chromatin (or 
nuclear body), both of the male and of the female nucleus, enters into 
the formation of thé cleayage-nucleus. The division of this last, 
formed, as we have seen, by copulation, differs in no essential respect 
from the karyokinetic (indirect) division of other cell-nuclei. All 
the filamentar forms, with unimportant changes in certain phases, are 
exactly similar to those already noted when describing the division of 
the nuclei of the cells of tissue. The mother-star of the karyokinetic 
figure has not the same centre as the radial arrangement of the ovarian 
protoplasm, The radial forms of the daughter-nuclei have, however, 
the same centre; but this is true also of other than ovarian cells. 

The author insists on the fact that most ova are very unsuitable 
objects for the study of dividing nuclei; the observations by him on 
this subject were carried out at Naples on Sphcerechinus brevispinosus, 
Echinus miliaris, and Toxopneustes lividus. 

Dealing with the phenomena of nucleus-division in the walls of 
the embryo-sac of Liliwm and other plants, Flemming directs attention 
to the results of Strasburger, from which his own differ considerably. 
He finds that in all nuclear figures there are many more chromatic 
filaments than that author has represented, and that these do not 


> * Aych, Mikr. Anat., xx. (1881) pp. 1-87 (4 pls.). 


318 SUMMARY OF CURRENT RESEARCHES RELATING TO 


present considerable enlargements or diminutions in size, but that 
they are either all of the same thickness, or only here and there 
present variations, and these of the very slightest character. There 
is no compact plate in the equatorial plane, but only closely packed 
coils ; in this plane there is frequently to be observed a clear medulla, 
the presence of which appears to have escaped the notice of Stras- 
burger. After carrying these criticisms further, attention is drawn 
to many points in which there is a resemblance between the cells of 
the tissues of animals and plants. 

Further studies have been made on karyokinesis and the structure 
of the nuclei. As to the latter, we may note that the author finds 
that what he has called the “intermediate substance” of the nucleus 
contains, after treatment with reagents, and probably also during life, 
a fine continuation of the nuclear network. The fine granulation 
which may be seen in the intermediate substance of the nucleus with 
less powerful lenses, and which was formerly thought to be due to 
coagulation in a homogeneous mass, is to be referred to this fine frame- 
work; the bars, so to speak, of which it is made up are the direct 
continuation of the coarser, and are chromatic. It is, perhaps, to the 
presence of these that we have to refer the possibility of colouring 
the intermediate substance of the nucleus. The nuclear envelope, so 
far as it is capable of being coloured, consists of small peripheral 
enlargements of these bars, and is formed of the same substance as 
they are. The question whether there is an achromatic membrane 
enclosing the nucleus cannot yet be decided. 

After giving some account of the polar corpuscles, Flemming 
points out that the angles of the filamentar loops, which go to form 
the stellate chromatic figure, are often distinctly in contact with one 
of the achromatic fibres; the paleness and fineness of the latter are so 
extreme that never more than a part of them has ever yet been 
detected ; from what he has seen, however, he concludes that this 
touching of a chromatic loop with an achromatic filament corresponds 
to the natural position. It would follow, therefore, that the angle of 
the loop has been attracted by the filament, and that later on the 
loops, when the mother-figure divides, would become arranged in two 
groups. 

In some examples of the star or circlet-forms the chromatic fila- 
mentar loops lie so freely that they can be counted, with the aid of 
oil-immersion objectives and Abbe’s illuminating apparatus, In the 
epithelial cells of the buccal and branchial epithelium of the larve of 
salamanders four-and-twenty loops were in three cases quite dis- 
tinctly made out. In other cases from 17 to 22 were less distinctly 
seen, and the possibility is that in these cases there were really 24 
filaments also. 

Dealing lastly with some observations on cell-division in Man, 
it is stated that in the epithelium of the cornea of an adult subject, 
the lowermost layers exhibited rare and scattered cell-divisions, but 
here again, just as in Salamandra maculata, the chromatic figures were 
detected, but the achromatic could not be seen, so small was the 
object. In the blood of a leucocythemic patient cell-division with 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 319 


kinetic figures was seen; the blood was excessively rich in colourless 
cells, and had a yellowish-white colour; of several thousand cells, it 
was computed that only one per thousand exhibited karyokinesis. 
From this it may be concluded either that in leucocythemia the 
colourless cells multiply by direct constriction of the nucleus, or that 
indirect cell-division chiefly occurs in the spleen and osseous medulla, 
so that it is only rarely that cells are caught dividing in the blood 
itself. Dealing with some deviations from the ordinary mode of cell- 
division in sarcoma and carcinoma, the author takes the opportunity 
of insisting on the fact that as an ordinary rule, nuclear division is 
on the same type in man as in the Amphibia. 

Summing up the results at which he has here arrived, Flemming 
finds that in different objects—ovarian cells, plant-cells, and human 
epithelia—he has again been able to demonstrate that the physical 
processes and the corresponding mechanics of kinetic nucleus-division 
is, or appears to be, everywhere essentially the same; at any rate, 
there is no reasonable ground for doubting this uniformity. He then 
passes in detailed review the doctrines of Strasburger, a résumé of 
which it is impossible to give here. The author states that he sees as 
yet no ground for doubting that the nucleus is a division-organ for 
the cell, whether or no it has other functions in addition. This view 
is the only one which explains the general presence of the nucleus and 
the complicated kinetic processes of division. The phenomena ob- 
served in the nucleus may lead us some day to a true physiology of 
cell-division, and everything which bears, howsoever slightly, on 
this point, appears to be of much more importance than any merely 
morphological facts. 

In using the term “ homology of the processes,” no reference has 
been imagined to phylogenetic considerations, and if serious objection 
be taken to its use, we have only to replace it by “ homotypy.” The 
questions raised in this connection by Strasburger have no importance 
for the histologist. 


Theory of Ameboid Movements.*—Mr. J. B. Haycraft endeavours 
to account for the throwing out and subsequent retraction of the 
pseudopodia (of white blood-corpuscles and unicellular organisms), 
“pointing out, it may be, but one factor, but that a probable one.” 

The author’s suggestion is that in those corpuscles which exhibit 
amceboid movements, they are due to contractions of the stroma or 
network of the protoplasm, which contracts at every part except where 
the pseudopodium springs from, forcing the interstromal matter at 
this point through the aperture left patent. 

“This accords well with the fact that the pseudopodia seem 
actually to be projected always as radii from the cell, and that they 
are of a very hyaline nature. The difficulty is to comprehend the 
forces engaged in their retraction. There are probably at least 
three :—(1) the relaxation of the stroma; (2) the viscosity of the 
substance; and (3) surface tension, in virtue of which a body tends to 


assume the spherical shape. 
* Proc. Roy. Soc. Edin., xi. (1881) pp. 29-33. 


b] 


320 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Now this may be very well theoretically, but are these three 
factors equal to the occasion ? is the question before us. I have imitated 
the structure of the Ameba in the following way :— 

An indiarubber ball is pierced by two or three holes near together ; 
these should be about the diameter of a common darning-needle. A 
larger aperture (half an inch across) is then made in the ball, but 
opposite to the smaller holes, and the ball half filled with white 
of egg (unboiled) tinted with magenta. The ball represents the 
stroma, while white of egg takes the place of the interstromal 
matter. The ball is now dipped into a beaker of water to which 
sugar has been previously added until its specific gravity is equal to 
that of white of egg. Place a finger over the aperture through which 
the ball was filled, and press upon it with the other fingers of the 
same hand. Beautiful little magenta-stained pseudopodia will be 
projected from the small apertures into the sugar solution, and on 
relaxing the pressure, still keeping the finger over the aperture above, 
the pseudopodia will be completely retracted. I have been able in 
this way to project them three or four inches, and afterwards they 
have been completely retracted. 

One might use common water in place of sugar solution, but as 
the specific gravity of the white of egg is greater than that of the 
water, the pseudopodia, when they have been projected more than an 
inch or so, break off and fall to the bottom. ‘The size of the aperture 
is also rather a nice point, for there is one size—roughly ,; inch in 
diameter—which is best suited for white of egg, although any sized 
aperture will answer, though not so well. This no doubt varies with 
the fluid used; ordinary ink may be substituted for white of egg, and 
oil for the sugar solution.” 

The author cannot but believe that in the stroma the active cause 
for these movements is to be sought for, and, as faras he can see, 
the mode described above for its action is least in antagonism to 
known facts. 

While, no doubt, many of the bulgings seen in the white corpuscle 
of the newt’s blood are due to changes in shape of the whole cell, 
probably with slight local accumulation of interstromal matter, yet 
may it not be that many of those fine hyaline processes are but inter- 
stromal matter projected from the cell ? 


Distinctions between Organisms and Minerals.*—In 1878 G. 
Fournier, by mixing together certain inorganic salts, produced pseudo- 
organisms, which in form and structure might easily have been con- 
founded with cryptogamic plants, and similar experiments have now 
been made by D. Monnier and C. Vogt, who describe them as 
follows :— 

Figured elements presenting all the -characteristics of form 
belonging to organic elements, such as cells, simple and with 
porous canals, tubes with sides, with septa, and with heterogeneous 
granular contents, may be produced artificially in an appropriate 
liquid by the joint action of two salts forming by double decom- 


* Comptes Rendus, xciv. (1882) pp. 45-6. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 321 


position one insoluble salt or two such. The one of these salts must 
be dissolved in the liquid, whilst the other must be present in a solid 
form. 

These forms of organic elements (cells, tubes, &c.), being produced 
either in a liquid of organic or semi-organic origin (such as the 
saccharate of lime), or an absolutely inorganic liquid (e. g. silicate of 
soda), there can be no longer any question of distinctive forms cha- 
racterizing inorganic bodies on the one hand and organic on the 
other. 

The formation of such pseudo-organic figured elements depends 
on the nature, the degree of viscosity, and the concentration of the 
liquids in which they are produced. Certain viscid liquids, such as 
solutions of gum arabic, or of zinc chloride, yield nothing of the kind. 

The forms of these pseudo-organic products are constant with 
reference to the salt employed, and constant also as any crystalline 
form of minerals. This characteristic form is so well maintained 
that it may even serve for the detection in mixtures of a very minute 
proportion of a substance. This form may be employed as a means of 
analysis, as sensitive as spectral analysis, and to distinguish for 
instance the alkaline carbonates, sesqui-carbonates, and bi-carbonates 
from one another. 

The form of the artificial pseudo-organic elements depends prin- 
cipally on the acid which enters into the composition of the solid salt, 
The sulphates and the phosphates in certain cases produce tubes, 
whilst the carbonates give rise to cells. 

With some exceptions, such as copper, cadmium, zinc, and nickel 
sulphates, the pseudo-organic forms are only produced by means of 
substances which are found in real organisms. Thus the saccharate 
of lime produces organic forms, whilst those of strontia and baryta do 
not. 

The artificial pseudo-organic elements are enveloped in true mem- 
branes possessing a high degree of dialysing power, and giving 
passage only to liquids. They have heterogeneous contents, and 
produce in their interior granulations arranged in a reeular order. 
They are, therefore, both in form and constitution, absolutely similar 
to the figured elements of which organisms are constructed. 

It is probable that the inorganic elements contained in organic 
protoplasm play a certain part in the constitution of the figured 
organic elements for the determination of the forms which those 
elements present. 

It is suggested * that by these experiments one of the characters 
by which mere lifeless matter was till yesterday differentiated from 
the living organism is wiped out. There are no longer any distinc- 
tive forms by which we may distinguish the two great classes, and it 
is asked whether it is not very possible that such structures might be 
produced without human intention and interference, in what may be 
called an accidental manner? Might they not, considering the large 
proportion of silica which they contain, become preserved for ages, 
and continue to display pseudo-organic features ? Suppose we find, in 


* Journ. of Sci., iv. (1882) pp. 148-53. 


322 SUMMARY OF CURRENT RESEARCHES RELATING TO 


a rock, certain structures exhibiting apparently organic cells, are they 
the remains of true organisms or of pseudo-organisms? ‘This con- 
sideration, at least till it has been further studied, is not without its 
bearing upon such questions as the organic or mineral nature of the 
structures found in meteorites, and, e. g., of Hozoon canadense. 


B. INVERTEBRATA. 


“Symbiosis of Animals with Plants ’’—Chlorophyll-corpuscles 
and Amyloid Deposits of Spongilla and Hydra.*—Professor E. R. 
Lankester discusses this subject in an interesting article, with special 
reference to the recent views of K. Brandt t (endorsing those of 
Semper) that the green-coloured corpuscles found in the cells of 
Spongilla fluviatilis and Hydra viridis are not similar in nature to 
the chlorophyll-bodies of plants, but are parasitic or ‘symbiotic ” 
unicellular alge. 

Whilst Professor Lankester considers that there is “ very nearly 
sufficient ground” for accepting the existence of “ symbiosis” so far 
as regards the “ yellow cells” of Anthozoa and Radiolarians, yet he 
regards Semper and Brandt's extension of it to Spongilla and Hydra 
as not justified. It appears to him that the green-coloured corpuscles 
found in the latter case are clearly similar in nature to the chloro- 
phyll-bodies of green plants, and that “there is no more reason to 
regard them as symbiotic alge than there is to regard the green 
corpuscles in the leaf of a buttercup as such.” 

In the course of the discussion it is pointed out that the investi- 
gation of the claims of any given greenish-coloured pigment to be 
regarded as “chlorophyll” is by no means a simple matter. Sup- 
posing the pigment to be soluble in alcohol, we still have to ascertain 
which of Sorby’s three groups (chlorophylls, xanthophylls, lichno- 
xanthines), are present, and which of each of the species distinguished 
by him within those groups. 

In order to do this we have to rely on :— 

Ist. Variations in degree of solubility in such media as alcohol, 
ether, benzine, carbon bisulphide. 

2nd. Absorption spectra of the series of solutions obtained. 

3rd. Fluorescence and spectrum of the fluorescent light of such 
solutions. 

4th. Reactions of the solutions with acids, alkalies, and oxidizing 
and reducing agents, which give rise to new compounds or change 
the spectra characteristically. 

There are, however, two other categories of phenomena in relation 
to the chlorophyll-bodies of green plants which comprise data of a 
nature to assist us in judging of the similarity or dissimilarity of the 
green pigments of animals compared with that of the chlorophyll- 
bodies. There are, 5thly, the physiological activities associated with 
the chlorophyll-bodies of plants; and 6thly, the morphological features 
of these bodies. ; 


* Quart. Journ. Micr. Sci., xxii. (1882) pp. 229-54 (1 pl.). 
+ See this Journal, ante, p. 241. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 323 


If we find in an organism physiological processes associated with 
the presence of a green pigment, which processes are identical with 
those associated with the presence of the green pigment occurring in 
the chlorophyll-bodies of plants, we have so far a certain amount of 
evidence in favour of the identity of the green pigment in the two 
cases. And again, if we find that the green pigment in an organism 
occurs in corpuscles which are morphologically similar to the chloro- 
phyll-bodies of plants, we have so far evidence in favour of the identity 
of the green pigment in the two cases. 

In the author’s view there is only one animal—Spongilla fluviatilis 
—in which the presence of chlorophyll has been definitely established 
by chemical and spectroscopical investigation (Dr. Sorby). The full 
corroboration by physiological and morphological evidence is still 
wanting, although to Mr. Geddes’ physiological researches on Con- 
voluta Schulz “ some value must be ascribed.” Similar physiological 
evidence in favour of the assimilation of the green pigment of Hydra 
viridis to that of green plants has also been obtained by Mr. J. E. 
Blomfield. 

A full statement is given of the author’s own observations with 
reference to the form under which the green pigment of Spongilla 
occurs, which confirm the spectroscopic evidence, and refute the view 
of Dr. Brandt that chlorophyll is never formed by animal organisms, 
but, when found in animal cells, is due to the presence of parasitic 
alge. No cell-nucleus really exists in connection with the green 
corpuscles of Spongilla or Hydra as asserted by Brandt, nor does his 
important observation of the formation of starch in isolated chloro- 
phyll-corpuscles tend in any way to prove that they are independent 
organisms but simply that a bit of protoplasm with its associated 
envelope or cap of green substance can retain its vital activity just as 
a piece of Ameba can. From Brandt’s account of his experiments in 
infecting Infusoria with the supposed parasites of Spongilla and 
Hydra,it is at once apparent that they are opposed to and not in 
favour of the parasitic theory. The chlorophyll-corpuscles of Spon- 
gilla were digested or else ejected by the infected Infusoria. In other 
eases the chlorophyll-corpuscles of Hydra remained in the Infusorian’s 
body unchanged. Had Brandt’s view been confirmed, the green 
corpuscle ought to have multiplied in its new host, and even such 
evidence of a temporary manifestation of vitality after removal from 
the Hydra or Spongilla would not be at all conclusive to the effect 
that the chlorophyll-corpuscles are independent organisms, and not 
parts of the protoplasm of the cell in which they are normally 
found. 

With regard to Hydra, a very strong argument against the sup- 
posed parasitism is found in the fact noticed by Kleinenberg that 
minute angular fragments of a given colour are often present together 
with the normal corpuscles. These present no difficulty if the 
corpuscles are regarded as products of the animal’s cell-protoplasm, 
but are inexplicable on the parasite theory. 

The final conclusion is that a careful study of the chlorophyll- 
corpuscles of Spongilla and Hydra reveals their correspondence with 


324 SUMMARY OF CURRENT RESEARCHES RELATING TO 


the known structure of the chlorophyll-bodies of plants; and those 
who, like Semper and Brandt, have supposed them to be parasites, 
have been misled, first by an imperfect acquaintance with the character 
of chlorophyll-bodies in general and of these in particular, and 
secondly by the plausible but delusive analogy presented by the 
“ yellow-cells ” of Radiolarians and of Anthozoa. 

There is a field for experimental inquiry in regard to animal 
chlorophyll, as it is very important to know whether it serves the 
same purpose as in the plant, and if so, whether we may not be able 
to get indications as to the disputed function of the green pigment 
which plants are unable to furnish. 


Paleontological Significance of the Tracks of Different In- 
vertebrates—Herr Nathorst has instituted some very interesting 
and important experiments in explanation of the traces in rock 
formations of various organisms. As we have not the original, we 
give the following report on it by T. Fuchs : * —“ In the sandstone 
and marl of all formations there are often found, in greater or less 
quantities, certain marks and imprints the nature of which has been 
hitherto problematical, as they have been interpreted either as alge 
or animals, or simply regarded as inexplicable. Such are the Fucoides 
Harlani from the Cambrian of America, the Nemertites of the culm- 
shales, the ‘ Zopfplatten’ (a term applied to flattened hair-like 
impressions) of the Jura, the endless varieties of different ‘ hiero- 
glyphs’ of the Flysch formation, as well as the various impressions 
described as Prolichnites, Hophyton, Spirophyton, Taonurus, &e. 

Nathorst has hit upon the happy idea of solving this problem by 
allowing different animals to crawl or run over soft mud, and then 
studying the tracks thus made by them. Although he has only 
experimented with about 40 marine animals, and a few insects, larvee, 
and earth-worms, still the result of his researches was truly astonish- 
ing, as he succeeded not only in artificially representing the finest 
Nemertites, Harlanie, ‘ Zopfplatten, Hophyton, &c., but he made the 
most unexpected discovery, that by far the greater number of the 
so-called ‘ Fucoids’ (e.g. Buthotrephis, Chondrites bollensis, Ch. 
hechingensis, and even the Fucoids of the Flysch, are nothing else 
than branched worm-tubes. However unexpected this discovery may 
be, there can hardly exist a doubt as to its accuracy after the experi- 
ments and evidence of the author. On taking several worms of the 
species Goniada and Glycerea, which are found in great numbers on 
the coasts of Norway, and allowing them to crawl over soft mud, he 
observed, to his astonishment, that they invariably made a branched 
track, like the twigs of a tree. They first advance a short distance, 
then go back a little over the track, and turn away on one side, thus 
producing a branch; this they repeat from different points and on 
different sides, finally returning to the point whence they started, 
and make a second main track in another direction, which they 


* HWandl. K. Svenska Vetens. Akad., xviii. (1881). Verh. k. k. Geol. 
Reichsanst., 1881, p. 346. See Naturforscher, xv. (1882) pp. 113-16. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. D2) 


branch in the same manner as before. In this way a whole tree is 
produced. 

This manceuyre is carried out by the worms, not merely on the 
surface, but they also burrow into the mud and from a given point 
produce a system of branched tubes, which being lined with a slimy 
coating, acquire a certain firmness. If a thin mixture of plaster of 
Paris be carefully poured over this perforated mud or clay, it will 
enter the tubes, and by carefully washing off the mud after the plaster 
is fixed, the cast of the tubes will bear the appearance of a delicate 
tree. 

If it is assumed that a bed of mud or clay can be thus burrowed 
by Goniada and Glycerea, and that the burrows can be filled with a 
soft substance, there will consequently be seen in a section of this 
bed, branched impressions which have the appearance of Alge, but 
which are, in reality, branched tubes made by worms. 

With regard to the fossil Chondrites, especially Chondrites bollensis 
and hechingensis, and the Chondrites of the Flysch, it had already 
occurred to many that these so-called Fucoids did not lie, like other 
fossil plants, pressed flat between the strata, but that they were found 
much more nearly in their proper form in the beds of marl, as though 
they had grown through them. It was also remarkable that they 
were never found in a carbonaceous condition, but invariably in marl. 
Heer has also drawn attention to the fact that these ‘ Fucoids’ occur 
in all formations, from the las to the upper eocene, in almost 
identical forms, while in existing seas hardly any analogous specimens 
can be found. This fact was the more inexplicable when it was con- 
sidered that, for example, the alge of the Paris limestone, or the 
Flysch of Monte Bolea bore the closest resemblance to the existing 
forms of alge, so that at the period of the eocene formation, types 
of algze existed analogous with the present. 

There were also other difficulties. Algze always grow only in 
small depths on a firm foundation, and never in mud. Now the 
localities in which the so-called Fucoids are found in the greatest 
quantities are manifestly formations of mud, and deposited in a deep 
sea..* 

All these difficulties at once vanish when it is known that these 
so-called ‘ Fucoids’ of the Flysch are not alge, but only the tracks 
of worms; the peculiarity of their origin is then no longer incom- 
prehensible. Worms are to be found in the sea at a great depth, 
and like especially slime and sand ; and it thus becomes evident that 
such perishable impressions as those made by worms are more lasting 
in the deep sea than in the formations nearer the shore, because they 
are not so easily effaced or disturbed. 

Among other marks observed by Nathorst, the following may be 
mentioned :—Corophium longicorne (a Crustacean) makes an impression 


* It might of course be assumed that alge, like Sargassum, torn from the 
place where they grew, and driven out to sea, finally sink down into the mud of 
the deep sea, but even with such an hypothesis these Algze would always appear 
unusual and accidental, while the Chondrites in the Flysch have a constant 
characteristic. 


326 SUMMARY .OF CURRENT RESEARCHES RELATING TO 


which corresponds exactly with the ‘Zopfen’ of the so-called 
‘ Zopfplatten’; Idothea baltica forms Prolichnites; a Planarian 
makes a flat, ribbon-like track ; Montacuta makes dentated impres- 
sions, which closely resemble Graptolithes; an unknown animal 
makes a regular, zigzag, serpentine mark ; a piece of an alga drawn 
over mud produced a streaked mark which corresponded exactly with 
what is described as Hophyton, and which has hitherto been considered 
a plant. Similar impressions were made by the tentacles of Meduse. 
Drops of water falling upon mud covered with a thin stratum of 
water produced remarkable, regular, wheel-shaped figures, which at a 
distance recall Meduse. An earthworm made an impression very 
similar to what is usually described as Spirophyton, and hitherto con- 
sidered an alga. This was produced in the following manner :—In 
creeping over the wet mud, the worm suddenly came to a stand; and 
while its hinder part remained motionless, the anterior was stretched 
out, while it at the same time bent itself so much to the side that 
its head was brought close to the other extremity of the body. 
After the front part had thus been stretched to its fullest extent, it 
was suddenly drawn back again, without, however, altering the 
position of the hinder part and the head. 

A complete review is also given of the marks of animals found in 
the Swedish rocks, and a catalogue of 129. publications in which these 
marks are described and illustrated. At the end of the list is a work 
by Saporta and Marion, which appeared about the same time as 
Nathorst’s, with the title, ‘L’évolution du régne végétale, les Cryp- 
togames.’ In this the authors endeavour to explain, according to 
the Darwinian theory, the gradual evolution of plants from the earliest 
stages, through the series of geological formations to the present day. 
Unfortunately” (it is said), “the greater number of fossil remains 
regarded in this book as plants are in reality the marks of worms.’* 

Nathorst has also published a second interesting paper + on the 
origin of particular marks, which Herr Fuchs abstracts as follows :— 

“‘ Some time ago peculiar unknown bodies were found in the Cam- 
brian strata of Lugnas in Sweden, which were described by Torell 
and Linnarson under the names of Spatangopsis costata and Astylo- 
spongia radiata. 'These bodies are in the form of 4-5 rayed stars or 
4-5 cornered pyramids, which either lie free in the mud, or with 
the under surface adhering to the rocks, or form only an impression 
onaslab. Between the rays and corners are occasionally to be seen 
crescent-shaped projections. When Nathorst was at Oeresund in 
1880, it happened that a large number of Aurelie were thrown on 
the shore. The animals all lay with the mouth downwards, and 
when he took one up he observed that it had sunk in the soft ground 
by its own weight, and that its gastrovascular system had made a 
star-like impression, showing the most striking resemblance to the 
so-called Spatangopsis. He then followed up the matter further, 
partly by making impressions of various Meduse, and partly by 
filling up their gastrovascular system with plaster, and so obtained a 


* A rather too sweeping assertion. —Ep. 
{+ Handl, K. Svenska Vetens, Akad., xix. (1882). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 327 


east. The preparations thus made corresponded so exactly in every 
detail with the problematical bodies from the Cambrian, that no doubt 
could exist as to their identity. The stars and pyramids are casts of 
the gastrovascular systems of the Meduse, the rays of the stars and 
the angles of the pyramids correspond with the arms, and the 
crescent-shaped projections occasionally occurring between the angles 
are casts of the genital cavities. The impressions on the slabs of rock 
are produced by Meduse thrown on the shore, and which, sinking 
more or less into the soft ground by their own weight, make a more 
or less complete impression of the body-cavity. The bodies lying 
free in the clay were probably produced by Meduse which lay on 
their backs, their gastrovascular system becoming filled up with sand 
or mud. There are some Meduse which do not swim, but sink into 
the mud on their backs, and lie still watching for their prey. 

The fact that the number of rays in these fossils varies from 4 
to 5 is not an objection to their medusoid nature because in the 
present day individuals are found with 5, 6 or 9 rays. Certainly 
this deviation from the normal number appears more frequently in 
the Cambrian Meduse than in the existing species. 

The impression of the disk and traces of the tentacles are still 
distinctly seen round a four-rayed star on a rock from Lugnas. 
Many slabs are covered with thick, spiral, vermicular bodies, which 
Nathorst considers to be arms torn from Meduse. Certain thread- 
like marks on sandstone were supposed by him to be made by 
swimming Meduse that grazed the ground with their tentacles. He 
was also of opinion that the so-called Hophytes, which occur in 
great quantities in the same strata as the Meduse fossils, were 
without doubt produced by creeping Meduse. 

The following species of Medusee from Lugnas have been dis- 
tinguished by him: (1) Medusites radiatus Linnars. sp.; (2) Medusites 
Jfavosus n. sp.; (3) Medusites Lindstromi Linnars. sp. 

Hitherto Medusz were only recognized with certainty in the 
Solenhofen slate, and the discovery of Nathorst is therefore of 
great interest. It is especially interesting also because these 
Meduse occur in the deepest strata that have ever produced fossils, 
so that they must be reckoned as amongst the oldest animals whose 
tracks are known to us.” 


Lymph of Invertebrates.*—C. I’. W. Krukenberg obtained 12-14 
drops of pure lymph from a medium-sized Hydrophilus piceus; he 
finds that the lymph varies remarkably in different individuals, the 
colour being different even when the specimens have lived under the 
same conditions. The coagulation which is spontaneously formed in 
it is, compared with that of the hemolymph of Mollusca and Crustacea, 
of a more membranous nature, and not gelatinous; the lymph under- 
goes coagulation at a comparatively low temperature. The melanotic 
change of colour presents remarkable individual variations, which lead 
to the belief that the body which blackens immediately on exposure to 
the air is in certain cases preformed in the circulating lymph. The 


* Verh. Nat. Med. Ver. Heidelberg, iii. (1881). 


328 SUMMARY OF CURRENT RESEARCHES RELATING TO 


hemolymph of Planorbis, like that of Vermes, does not coagulate 
spontaneously; the coagulation temperature is very different to that 
of the hemolymph of the Gastropoda, for while this coagulates at 
60° C., a small amount of fiuid can be filtered from the former at 
64° C. The coloration of the fluid of Planorbis is solely due to its 
hemoglobin, but the intensity of the colour is never so marked as it 
is generally in the Mammalia. 


Mollusca. 


Development of the Cephalopoda.*— Dr. M. Ussow, in describing 
the formation of the germinal glands, points out that the unpaired 
ovary is aconical sac occupying the lower part of the trunk, and often, 
when mature, of considerable size. The ripe ova fall into the ccelom, 
and thence by the ciliated epithelium are carried to the oviduct. By 
the antiperistaltic movements of these latter, they are conveyed into 
the respiratory cavity, and thence by the contraction of the funnel to 
the exterior. The Graafian follicles are so arranged that the central 
portion of the ovary is occupied with the younger or with the primor- 
dial ova. Each follicle has a separate theca, which is well provided 
with blood-vessels coming from the genital arteries. The first rudi- 
ments of the germinal glands appear during the periods of embryonic 
development, the small group of rounded mesodermal cells which 
appear in the third developmental period near the narrow end of the 
mantle and behind the systemic hearts, being, undoubtedly, converted 
into evarian glands or sperm-glands. Further development, and the 
formation of the efferent ducts appear to be post-embryonic. During 
these changes the mesodermal cells become converted into a number 
of racemose Graafian follicles, the walls of which are formed by the 
thin theca, and by a uni- or bilaminate membrana granulosa. A pri- 
mordial ovum and the formative yolk are nothing more than a differ-' 
entiated and greatly developed epithelial cell of the ovary. As the 
cell grows the Graafian follicles increase in size; folds then appear 
owing to the development of the granulosa-cells, their glandular inner 
surface increases, and secretes the nutrient fluids. The chorion is 
not formed till the secretion of the yolk is completed, and when it is 
formed there appears the micropyle; the chorion is elastic and trans- 
parent. Beneath it in the mature egg there is an inconsiderable 
quantity of fluid, which coagulates on heating, and within this there 
is the formative yolk, formed of a finely granular protoplasm and 
investing the less fluid nutrient yolk. 

The first developmental period extends from the commencement 
of segmentation to the first appearance of the rudiments of the organs; 
there appears to be a striking similarity in the phenomena exhibited 
by different members of the group. At first all the cleavage-cells 
appear at one pole of the egg, the grooves extending from the central 
portion of the formative yolk outwards; the nutrient yolk is regarded 
by the author, in opposition to Prof. Lankester, as playing a merely 
passive part. Cleavage is at first superficial and only gradually 
extends to the more deeply lying parts; in Argonauta argo there was 


* Arch. de Biol., ii. (1881) pp. 553-635 (2 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 529 


an interval of about one or two hours between fertilization and the 
appearance of the first two segmentation-spheres ; in the other forms 
from 5-8 hours. After describing the process of segmentation in full, 
and discussing the results of earlier observers, Dr. Ussow passes to 
the next step, in which the blastoderm, &c., are developed. In the 
germinal disk it is possible to distinguish (1) the central portion, 
(2) the median portion, or area opaca, more or less ring-shaped in 
form, and (3) the lower protoplasmic portion, not yet differentiated 
into cells and continued as far as the lower pole of the egg. The 
central portion is formed by a single layer and consists of small, 
polygonal cells derived from the division of the six primary and two 
secondary cleavage spheres. In the fresh condition the finely 
granular protoplasm and the sharply contoured nuclei are quite 
transparent. The cells are almost all of the same size (0°016 mm.), 
the peripheral ones being alone somewhat larger. At first flattened, 
they gradually become cylindrical; and frequently alter in form by 
dividing longitudinally. ‘The cells of the area opaca are longer, un- 
equal in size, and polygonal in form; there are only two or three 
concentric rows; they owe their origin to the multiplication of those 
cleavage-cells which had been separated off by the development of 
the equatorial groove. They are dark in appearance, owing to the 
consistency of their protoplasm, and the thickness of the layer. The 
broadest and lower portion consists at one time of 32 segments, which 
are frequently arranged in pairs; as there is not a single large 
cleavage-cell, but 2-6 cells at the thickened apex of each segment, the 
edge of the germinal disk is irregular and villous owing to the pro- 
jecting angles of the cells; between each pair of segments there is a 
clear intermediate space, filled up by an extremely thin layer of the 
formative yolk; this disappears as the blastodermic cells multiply. 
A little later (86th hour) there appear the rounded cells of the 
mesoderm ; these arise from the cells of the median portion, which 
undergo transverse division ; each of the cells so formed is rounded, 
and gradually takes on a cylindrical form. As soon as these cells 
appear the process of division begins to affect all the cells of these 
parts of the germinal disk, and is effected either transversely or lon- 
gitudinally. Three or four successive rows of the larger blastoderm- 
cells, forming the median portion, divide longitudinally as soon as 
they have divided transversely ; this, of course, increases the breadth 
of the median portion, which algo becomes a thicker and therefore a 
darker ring; this ring surrounds the unilaminate and still transparent 
central portion. The other six days of the first developmental period 
are occupied by the multiplication of the cells of the peripheral 
portion of the germinal disk; the upper and median germinal layers 
extend over the surface of the nutrient yolk. 

At the end of the second day of development the middle layers 
consist of several rows of cells; at the same time the ectodermal cells 
have continued to undergo transverse division, and have thus narrowed 
the central portion of the germinal disk. On the third day, separate 
groups of mesodermal cells make their way into the central portion, 
and towards the end of that day the upper limits of the mesoderm 

Ser. 2.—Vor. II. Z 


330 SUMMARY OF CURRENT RESEARCHES RELATING TO 


are brought nearer to the superior pole of the egg. The layer which 
in all Cephalopods forms the wall of the outer yolk-sac, appears to 
the author to be simply formed of mesodermal cells, of which it 
would appear to be a direct continuation. The various facts which 
Dr. Ussow has observed lead him to think that in the Cephalopoda 
the mesoderm is not folded off from the ectoderm, but simply arises 
from the transverse division of the cells of that layer. Later, the 
diameter of the unilaminate central portion decreases considerably, 
while the median zone grows both centrifugally and centripetally. 
The cells of the ectoderm at first vary in form and size in different 
parts of the embryo; later on they all become short epithelial cells ; 
but it is not till the ninth or tenth day that they are to be sharply 
distinguished from all the rest, and they are then cylindrical in form. 
The mesoderm grows in two directions, towards the central portion 
of the germ and the equator of the egg. 

Contrary to the opinion of Kélliker and others, the author is con- 
vinced that all the Cephalopoda begin to develope from the dorsal 
side, and not from the hinder end of their body. Further observations 
are promised. 


Development of the Oyster.*—Dr. R. Horst points out that the 
groove or depression described by Davaine and Lacaze-Duthiers is 
the invagination of the embryo, and that the dorsal depression regarded 
by Brooks as being the opening of the intestinal tube is really the 
shell-gland-invagination. These two inpushings, possessed by the 
oyster at one and the same stage, are almost equally well developed ; 
later on the ventral side becomes a little pushed out so as to form a 
kind of foot. The abdominal cavity is formed by the separation of 
the ectoderm from the endoderm. The author confirms the doctrine 
of Salensky and Hatschek that the first rudiment of the shell is an 
unpaired formation, and he thinks that this is true of all Mollusca; 
Carbonate of lime is very early deposited in the shell. The white 
spat becomes black spat by the deposition of pigment at different 
points in the body of the larva. On the ventral face there is a 
button-like thickening of the ectoderm, which is probably the com- 
mencing rudiment of the otocyst. 


Abortion of Reproductive Organs of Vitrina.j—F. dA. Furtado, 
on examining seven specimens of Vitrina from the Azores, found 
that there was not the least trace of any reproductive organs, and 
Professor L. C. Miall confirms the observation as regards three other 
specimens sent to him, Abortion of the reproductive organs has 
been observed in animals infested by parasites, e. g. in stylopized bees, 
in Lymnea stagnalis when attacked by Trematodes, and in female 
hermit-crabs attacked by Rhizocephala. The complete abortion of 
the parts, writes Professor Miall in the remarkable case described by 
Mr. Furtado, distinguishes it at once from the many cases of real or 
supposed functional defect met with in hybrids. 


* Zool. Anzeig., v. (1882) pp. 160-2. 
t+ Ann. and Mag, Nat. Hist., ix. (1882) pp. 897-9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 331 


Morphology of the Amphineura.*—Dr. A. A. W. Hubrecht gives 
a convenient summary of the actual state of our knowledge of this 
class of animals, including a brief statement of what is “ known, 
surmised, uncertain, or unknown,’ with respect to (a) integument, 
(b) nervous system, (¢) intestine, (d) circulatory and respiratory 
apparatus, (€) reproductive and excretory organs. 


Molluscoida. 


New Synascidian.j—Dr. R. Drasche describes Oxycorynia fasci- 
cularis, which are found in cylindrical trunks of as much as 6 cm. 
in length; the colour of the colony is a dirty green, and the in- 
dividuals which are only 10 mm. long have the branchial sac 6 mm. 
long. The rounded cloacal orifice is found at the uppermost tip of 
the sac. The animals are connected together by a very delicate and 
transparent tunic. The nearest ally would seem to be the Chon- 
drostachthys of Macdonald, 


Alternation of Generations in Doliolum.t—Dr. Carl Grobben 
describes this phenomenon in detail, and amongst more general 
considerations, points out that nearly all animals which reproduce 
themselves by gemmation are of a fixed habit, the matter which is 
not used up in the work of locomotion being applied to the pro- 
duction and nutrition of buds; gemmation being inconveniently 
carried on by a free-swimming form, we must suppose that such free 
forms as do multiply thus are derived from ancestors that were fixed ; 
we have a good example in the Siphonophora, and the same view 
may be applied to the Salpide. 

The simplest mode of alternation of generations is, perhaps, to 
be seen in some compound Ascidians, where the individuals that 
arise from ova are sterile, while those that are developed from buds 
develope generative organs. This is a division of labour. In 
Pyrosoma the ovum gives rise to a cyathozooid, whence appear 
four ascidiozooids, and these multiply either by gemmation or by 
the formation of sexual elements. In the true Salpide the nurse 
developed from the egg gives rise to a chain of apparently very 
different forms which are altogether sexual in their mode of develop- 
ment. Here then there is a complete division of labour, and this is 
clearly due to their free life. Coming lastly to Doliolum, we find 
that here the larva developed from the egg, after losing its tail, 
gives rise to lateral and then to median buds, which latter provide 
the sexual forms. The differences between the zooids are consider- 
able: the nurse has nine, the sexual form has only eight muscular 
bands ; the former has an auditory organ which the latter is with- 
out; the first nurse of Doliolum has its stolon dorsal, and is there- 
fore without a homologue in the rest of the Tunicata ; in other words, 
it is a structure which has been independently developed, and in 


* Quart. Journ. Mier. Sci., xxii. (1882) pp. 212-28 (11 figs. ). 
+ Zool. Anzeig., v. (1882) pp. 162-3. 
{ Claus’ Arbeit., iv. (1882) pp. 201-99 (5 pls.). 

Z% 2 


Sy SUMMARY OF CURRENT RESEARCHES RELATING TO 


consequence of its appearance the ventral stolon of other Tunicates 
has been arrested in its development, and has become a rudimentary 
organ. The appearance of this new, dorsal, stolon is explained by 
the inherited capacity of the Doliolida to produce new structures by 
gemmation, and its supersession of the ventral one by the following 
hypothesis: the dorsal stolon is shown to be more embryonic than 
the ventral one by the fact of its only being formed of the three 
germinal layers, and not, like the latter, of six rudiments ; we know 
that embryonic tissues have a much more considerable growth-energy 
than those that are more highly differentiated, and this advantage 
became more and more marked by the influence of heredity. The 
relations of the different generations is shown in the following 
diagrams, where a letter or a combination of letters marks a genera- 
tion, A ig a sexual, B an asexual generation, M the median, and L the 
lateral buds. 


Synascidiz. Pyrosoma. Salpa. Doliolum, 
AB AB A A 
Vigo * | | 
B AB B AB B BA 
Le tall / Sey eS | | \=L 
AB B AB AB B=As A [A] M 
| 
A 


Dr. Grobben next passes to the phylogenetic history of alterna- 
tion of generations in the Acalephz ; in the Hydroids, as Leuckart 
has shown, it is due to division of labour, in consequence of which 
only some individuals of the colony have produced generative pro- 
ducts, and the Medusz have been derived by natural selection from 
the free-swimming generative polyps. In the Acalephe the pheno- 
menon is likewise due to division of labour among the members of 
a colony. After a special reference to the studies of Professor 
Semper, the author passes to the Cestodes, where he does not discuss 
the question of the phylogenetic development, but merely raises the 
question whether we have here to deal with true alternation. He 
comes to the conclusion that it is not so, but that we have only a 
simple metamorphosis, the larva, vesicle, scolex, and strobila being 
one and the same individual in different stages of development. This 
is true of the common Tenia, but it does not apply to those cysticer- 
coid forms in which several heads are developed, for each head 
represents a T'enia-individual with the power of developing proglot- 
tids. The history of the Trematoda is dealt with in the same 
manner, and it is pointed out that we have here to do not with 
alternation of generations, but with heterogony. The author comes 
to the conclusion that the so-called spores are ova capable of de- 
veloping without fertilization; the generative products are either 
single cells (ova), or are derived from the germinal layers of the 
mother. In the one case we have sexual, and in the other asexual 
development ; or, in other words, unisexual and bisexual generations 
appear alternately in the cycle. 


Od 
Go 
Oo 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 


Arthropoda. 


a. Insecta. 


Nervous System of the Larve of Diptera.*—E. Brandt has 
continued his researches on the nervous system of insects.+ In the 
larvee of the Leptide, Bibionide, Therevide, Xylophagidew, and 
Dolichopodide (families whose nervous system has not hitherto been 
examined) there are thirteen ganglia, two cephalic, three thoracic, and 
eight abdominal. In the Leptide, the ganglia, instead of being joined 
by the simple commissures as in all other Diptera, are united by 
double nervous cords, as in the adult. In the next three families the 
two first thoracic ganglia are close to one another, while the third is 
further off. As the adult has only two thoracic ganglia, the first is 
evidently derived from the union of the first two of the larva. In the 
Dolichopodide the adult has no abdominal ganglia, and the second 
thoracic ganglion is therefore evidently derived from the fusion of the 
third of the larva with all the abdominal ganglia. 

Several genera and species of families which have already been 
partially examined are also described, and the author finds that in 
the Tabanide the larve have seven ganglia, and not two only, as 
described by J. Kiinckel d’Herculais. 


Occident Ants.t—Dr. H. C. M‘Cook publishes in a collected form 
his observations on the Honey Ants of the Garden of the Gods, 
which we have already dealt with in this Journal,§ and the Occident 
Ants of the American plains. 

The occident ants build mounds of from less than half a foot to 
more than a foot in height, round which they make a circular 
“clearing” of grass and other vegetation, presumably by cutting it 
away after the manner of the agricultural ants of Texas, previously 
described by Dr. M‘Cook. The mound is always covered with 
pebbles which have been removed in the process of excavating the 
underground chambers and galleries. Some of the pebbles so trans- 
ported are ten times the weight of the ant, so that the labour per- 
formed would be paralleled by that of a man if he could carry half a 
ton up a staircase one-third of a mile high. 

The ants do not begin their labour till eight or nine o’clock in the 
morning ; so that, as Dr. M‘Cook seems not unwilling to observe, 
“it might not be unmeet that those persons whose love of sleep 
during late morning hours has been disturbed by the familiar Scripture 
proverb, ‘Go to the ant, thou sluggard; consider her ways, and be 
wise!’ should return upon their mentors with the above-recorded 
facts, and cite this ant, who is indeed no sluggard, as being neverthe- 
less fond of a morning nap.” The day’s work, or at any rate the day 
of outdoor work, begins by opening the gates which had been closed 


* Comptes Rendus, xciv. (1882) pp. 982-5. 


+ See this Journal, i. (1881) pp. 234-5. 
t M‘Cook, H. C., ‘The Honey Ants of the Garden of the Gods, and the 


Occident Ants of the American Plains.’ 8vo, Philadelphia, 1882. Cf. Mr. G. 
J. Romanes in ‘ Nature,’ xxv. (1882) pp. 405-7. 
§ See this Journal, iii. (1880) pp. 242 and 775. 


334 SUMMARY OF CURRENT RESEARCHES RELATING TO 


the previous evening. ‘“ The manner of opening the gate cannot be 
fully described, because the work is chiefly done within and behind 
the outer door of gravel. The mode would doubtless be correctly 
indicated by reversing the process of closing gates presently described. 
What I saw was, first, the appearance of the quivering pair of an- 
tenn above one of the pebbles, followed quickly by the brown head 
and feet projected through the interstices or joints of the contingent 
grayel-stones. Then forth issues a single worker, who peeps to this 
side and that, and after compassing a little cireuit round about the 
gate, or perhaps without further ceremony, seizes a pebble, bears it 
off, deposits it a few inches from the gate, and returns to repeat the 
task ; she is followed sometimes cautiously and at intervals of ten, 
twenty, even thirty minutes, by a few other ants, who aid in clearing 
away the barricade, after which the general exit occurs. Again 
there is a rush of workers almost immediately after the first break, 
who usually spread over the hill, bristling around the gate, gradually 
widening the circles, and finally push out into the surrounding 
herbage. At first the exit hole is the size of a pea, perfectly round, 
and plainly shows that sand and soil have been used under the gravel 
to seal up the gate. The whole appeared to have been cemented, 
probably by the moisture of the night dew. 

‘The process of closing the gates is even more interesting to the 
observer than the opening, as the various steps are more under his 
notice. . . . At nest A the closing was chiefly from within. The 
workers pushed the sand from the inside outwards with their heads. 
A grass straw about an inch long was brought from the interior and 
pushed out until it lay across the gate as a stay for the filling 
material. Soil was here principally used for closing, a few pebbles 
being added.” In another case, “when the gate was nearly closed a 
straggling minor came back from the commons and essayed entrance, 
wherein she failed. Several trials and failures succeeded, whereupon 
she commenced dragging the dirt from the opening. While thus 
engaged the major approached with a huge bit of gravel, which she 
deposited on her comrade with as much nonchalance as though she 
were one of the adjoining pebbles. At last the minor dug out a 
tiny hole through which she squeezed into the nest, and the major, 
who was deliberately approaching close behind her, carrying another 
pebble, immediately sealed up the opening. During this amusing 
episode the straggler made no effort to aid in the closing, being 
wholly intent on entering, and the gate-closer paid no attention 
to her whatever, beyond the first sudden and satisfactory antennal 
challenge. Each moved forward to her own duty with the undisturbed 
plasticity of a machine.” 

This “ by-play ” between the gate-closers and the late-returning 
foragers is not the exception but the rule; nevertheless it does not 
appear that the foragers ever so far miscalculate their time as to 
arrive after the gates are completely closed. When the gates are all 
but closed there is generally but a single ant engaged in the closing 
process from without; this ant slips in at the last moment, and the 

process is finally concluded from within. The gates are similarly 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. B00 


shut during the day-time if the weather seems to threaten a heavy 
rain-storm. 

The ants, though provided with very formidable stings, are 
exceedingly mild and unwarlike. They present the same habits of 
“harvesting” as those which were previously known to occur in 
allied species of Florida and Texas. 


y. Arachnida. 


Pycnogonida.*—After a review of what has been done by pre- 
ceding naturalists, Dr. P. P. C. Hoek discusses the general form of 
the body ; this is strictly bi-lateral, with a proboscis, four segments, 
and a rudimentary abdomen. The first segment is formed of one 
cephalic and of one thoracic ring; the proboscis ought not to be 
regarded as a head, it varies in form, and in length, and in the mode 
of its attachment to the cephalothoracic segments. The body may be 
slender or robust, the segmentation distinct or obscured ; the abdomen 
is represented by a single joint, the length of which varies consider- 
ably ; the surface of the body may be smooth or hairy, with or without 
tubercles or spines. There are never more than seven pairs of 
appendages, and when all are present three belong to the cephalo- 
thorax, and are known respectively as mandibles, palpi, and ovigerous 
legs; when the first are complete, they have three joints and a 
terminal pincer (Pallenopsis); in some cases (Pycnogonum) the 
mandibles altogether disappear in the adult state. The palps would 
appear to have primitively a number of joints, and this number varies 
even within the limits of a genus. There may be ten joints or as 
few as three, or the palps may disappear altogether. The females of 
all species, however, retain the ovigerous legs, and they are frequently 
also represented in the male. The nervous system consists, as usual, 
of a cerebrum, an cesophageal collar, and a ventral ganglionic chain ; 
in the last there are four or five ganglia, Phowxichilus presenting an 
intermediate condition in having the first of its ventral ganglia small 
in size, and closely applied to the second; all are distinctly bilobate, 
the coalescence of the paired parts being complete. Concrescence 
never attains to the extent exhibited in the Brachyurous Crustacea, 
for even in Ammeethea it is possible, by the aid of reagents, to discover 
the connecting fibres. Nor, indeed, can external form be taken as 
giving any true idea of the extent of fusion, for Pycnogonum, in 
which there is an extreme condition of external ‘‘ concentration,’ has 
the ganglia separated by some considerable distance. After a further 
discussion of allied points, the author states the eyes of the Pycno- 
gonida have generally a very complex composition; ganglion-cells 
and rods can always be made out, but there would not appear to be 
any vitreous body; a lens is developed from the integument. The 
buccal orifice is triangular, and almost immediately dilates into a very 
large pharynx; at its end there is a constriction and a canal is 
developed, the length of which depends on that of the cephalic part 
of the cephalothoracic segment. ‘The inner face of the cells lining 


* Arch, Zool. Expér. et Gén., ix. (1881) pp. 445-542 (8 pls.). 


336 SUMMARY OF CURRENT RESEARCHES RELATING TO 


this latter are invested ina delicate chitinous layer. The termination 
of the cesophagus is not abrupt; its three inner faces are prolonged 
towards the interior of the intestine, and give rise to three outgrowths 
which have all the appearance of special glands; tubular prolonga- 
ticns are, as is well known, connected with the intestine, but, though 
they no doubt are very important physiologically, the author has 
grave doubts as to their morphological significance. 

Great difficulties seem to attend a satisfactory study of the circula- 
tory system; the heart has three cavities, at the end of each of 
which there is a pair of orifices ; it is probable that there is an aorta, 
although it has not yet been detected ; as the author has mentioned 
in his ‘Challenger’ report, the dorsal surface of the heart is 
remarkable for having no muscular fibres. 

The sexes may be easily distinguished, for, with rare exceptions, 
the males carry the fecundated ova. Contrary to what generally 
happens, the females have lost the primitive organization of the 
generative organs, while the males have been more conservative. For 
elaborated details on this, as on various other points, the author refers 
to his ‘ Challenger’ report.* 

Dr. Hoek would place the larve of Pyenogonids with the primary 
larve of Prof. Balfour. When we consider the zoological position 
and classification of the Pycnogonida, we are led to the conclusion 
that the doctrine of Semper, which regards them as Arachnida, 
has nothing to defend it; the only real point of resemblance 
between them lies in their having the same number of thoracic 
appendages; the similarity in the formation of the first pair of 
appendages, lately dwelt upon by Balfour, seems to the author to be 
of less significance than the fact that this organ is innervated by a 
nerve arising from the sub-cesophageal ganglion. Dr. Hoek thinks 
that the Pycnogonida must form a distinct class of the Arthropoda, 
comparable to the Crustacea, Insecta, &e. 

Starting from the protonymph, or larval form common to Asco- 
rhynchus, Nymphon, and Pycnogonum, and noting that in the two 
former there remain appendages, which become cephalic, while in the 
last they are during development obliterated, we have to consider 
Pycnogonum as the least ancient form, The doctrine suggested by the 
history of the metamorphosis is supported by a study of the nervous 
system; in the primitive condition the ventral part of the nervous 
system is represented by six ganglia, excluding the more or less rudi- 
mentary abdominal ganglia; of the six segments corresponding to 
these ganglia, four are thoracic ; and two, in a more primitive con- 
dition, belong to the cephalic part. As the mandibles are innervated 
by the subcesophageal ganglion, we have three pairs of cephalic 
appendages, and this is what is permanently seen in Ascorhynchus and 
Nymphon. This possession of three cephalic appendages is, by 
various evidence, indicated as the primitive arrangement. Nymphon 
retains this most unchanged, but the number of the joints in its 
cephalic appendages and the structure of the genital organs forbid us 
to regard it as the most ancient form now living. A hypothetical 


* See this Journal, i. (1881) p. 886. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 337 


primitive form or Archipycnogonum might be defined as a Pycnogonid 
of large size, with strong mandibles of three joints, and armed with a 
terminal claw, with long palpi of ten joints, with ovigerous legs of 
ten joints, the last four of which are spinous. The thoracic limbs 
have eight joints, and end in a claw, with two accessory claws. The 
descendants of this form are either delicate and have their limbs 
articulated at a considerable distance from one another, or they are 
robust and their limbs are set close to one another. Four natural 
families may be distinguished—Nymphonide, Ascorhynchida, 
Colossendeidz, and Phoxichilide—by the aid of the differences 
exhibited in the structure of the appendages. 


Spiders’ Webs.*—Mr. R. J. Lecky, referring to the discussion at 
the January meeting of the Society (ante, pp. 142-3), writes :—“ The 
geometric spider never spins a glutinous web; the entire net is first 
made, beginning with the long stays (those alone suitable for optical 
purposes), then those at the circumference, next the radial threads, 
finishing the net with the spiral ‘ratlins’ (to use a nautical expres- 
sion). When these are complete, the spinner begins at the ‘ratlin’ 
next to the exterior threads, and bedews them at regular intervals with 
the glutinous fluid, walking round and round until all is complete. 
This fluid spreads, in time, over the ‘ratlins, and so the thread 
appears as if spun in a glutinous state at the commencement.” 


6. Crustacea. 


Limulus a Crustacean.t—Dr. A. 8. Packard, jun., who has also 
devoted much attention to this form, replies to Professor Lankester’s 
paper on the Arachnid nature of Limulus,t maintaining that his 
conclusions are untenable. The criticism is not susceptible of 
abstract beyond the statement that Dr. Packard considers Professor 
Lankester has not correctly described the differences between the 
brain and the thoracic ganglionic mass of the scorpion and Limulus, 
that in the morphology of the brain the latter much more nearly 
approaches Apus and other Phyllopods than Arachnids, that four of 
the six segments described by Professor Lankester between the 
sixth abdominal segment and the spine are imaginary, as is also his 
view that the scattered simple eyes of the scorpion are really com- 
pound eyes, and some attempts to homologize parts of the scorpion 
with Limulus. 


Segmental Organs in Isopoda.t—Lereboulet in 1850 concluded 
that the Cloportides (Wood-lice) are allied to the Spiders, by the 
existence of special glands, secreting a silky substance ; but M. Huet 
considers that the facts he has observed would equally enable them 
to be referred to the Annelida or Myriapoda. 

There are glandular organs not only in the caudal region of these 
animals, but in each of the seven segments of the body. They are 
absent from the head. They open in the superior portion of the 

* Engl, Mech., xxxiv. (1882) p. 496. 
+ Ann. and Mag. Nat. Hist., ix. (1882) pp. 369-74. 
{ Comptes Rendus, xciy. (1882) pp. 810-11. 


338 SUMMARY OF CURRENT RESEARCHES RELATING TO 


epimera, on each side, in a sieve-like aperture. In the tail, the 
reduced segments do not show the “sieves,” the glands undergoing a 
sort of concentration, and all opening together in a slit pierced with 
holes arranged in linear series. This slit is on the external side of 
the external urostyle. 

Each of these glands consists of cellular elements of comparatively 
gigantic dimensions, some of them measuring 0°2mm. LEach is com- 
posed of a knobbed, indented, lobate body, always enclosing two 
large, symmetrical, granular nuclei, close to one another. Hach 
nucleus contains a nucleolus, also very granular. The nuclei are 
coloured red by carmine, and blue by iodized serum. Between them 
winds a sort of vestibule, from which issues a canal, filled with the 
secreted substance. The canals do not anastomose, but end separately 
in one of the sieve-like apertures, or in the slit of the urostyles. 

This arrangement is found in the greater part of the terrestrial 
Isopoda, Porcellio scaber, Oniscus murarius, Armadillo, and Ligia. 
_ Porcellio pictus has only the caudal glands. It is not found in any 
aquatic Isopod, nor in Ligia oceanica, nor in Anilocra, Idoteide, or 
Asellus aquaticus. 


Bopyride.*—R. Walz deals in order with the different parts of 
the organization of these parasitic Crustacea ; the cuticle of the male 
is said to be thicker than that of the female; the larval stages do not 
differ from one another in any important particulars; the changes 
early undergone by the mouth-organs are noted; later on, the oral 
cone calls to mind the suctorial proboscis of some Siphonostomata. 
On the inner side of the base of the first five pair of legs are deve- 
loped the brood-lamelle, which acquire their full size when the 
female reaches maturity; they are always membranous, and their 
chitinous cuticle is produced, as a rule, into short denticles. Vary- 
ing a good deal in form, they determine that of the brood-pouch. The 
gills are thin, lobate, rarely tubular appendages ; they always decrease 
in size from before backwards, and are, as a rule, better developed in 
the female than in the male; in the latter, indeed, they are often 
nothing more than small protuberances on the abdomen which dis- 
appear with age. Hach lamella consists of two folds with a very 
narrow intermediate space; from one wall there pass to the other 
supporting bars, which have a homogeneous clear appearance and are 
to be regarded as cuticular structures. The digestive apparatus 
exhibits special characters, in correspondence with the parasitic habits 
of its possessors; the fore-gut is first enlarged and then narrowed to a 
tube; it leads into a wider portion, and the whole is so arranged as to 
act as a suctorial pump. The fore-stomach is enlarged into a crop, 
and the inner wall of some forms is provided with a number of 
processes, by means of which there is a considerable increase of sur- 
face ; but this peculiarly arranged crop is, it is curious to note, found 
uly in the female and not in the male, where the corresponding 
region forms but a very slight enlargement. The mid-gut likewise 
is much smaller and narrower in the male than in the female. The 
salivary glands which have been described by Cornalia and Panceri, 


* Claus’ Arbciten, iv. (1882) pp. 125-200 (4 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 339 


were not detected by the author. There is a pair of hepatic tubes 
which give rise to numerous enlargements and lobes, but no lateral 
enlargements are to be found in the males. 

There is a well-developed heart in the form of a rounded oviform 
sac; in the irregularly developed female there is to be detected not 
only an asymmetry of form, but also of the position of the clefts. 
The wall of the aorta is formed by a clear transparent membrane, 
which never exhibits contractions; though efferent vessels are present, 
there are no afferent ones; a septum of connective tissue extends 
transversely below the enteron, just as in the Phronimida. 

The nervous system has only been examined by Rathke, and by 
Cornalia and Panceri; in its morphological relations it differs com- 
pletely from that of the other Isopoda; the brain is extremely 
reduced, as are all the parts connected therewith ; in the third thoracic 
segment is a reduced unpaired ganglionic chain, formed by the short- 

ening of the longitudinal commissures and the fusion of the ganglia; 

in this seven distinct elements may be made out. The peripheral 
nerve-trunks have a somewhat peculiar ganglionic relation. Those 
of the first go directly from their proper ganglion to the most anterior 
thoracic segment; the second pair passes below the third ganglion, 
and the next near the sixth, or, in other words, just in front of the 
termination of the nervous plate. The sensory organs are either a 
great deal reduced or have completely disappeared; in the young 
free-swimming male there are eye-spots and jointed, paired, antenne ; 
there is some question as to whether eyes can be said to exist in the 
female; at any rate true optic nerve-fibres are not always to be made 
out. The larve have reddish pigment-specks at the sides of the 
cephalic lobes, which are covered over by the base of the outermost 
pair of antenne. 

Not only do these parasites retain a separation of the sexes, but 
there is a well-marked sexual dimorphism ; the ovaries are dorsally- 
placed tubes, not fused with one another, the appearance of which 
varies with the age and condition of the animal; at first they are 
straight, but they gradually become provided with a number of lateral 
saccular diverticula, which project into the thoracic segments; the 
orifices of these organs are found, as might be expected, on the inner 
side of the bases of the fifth pair of legs. The wall of the ovarian 
tube is a thin membrane, invested internally by an epithelium and 
completely transparent. The male organs have much the same 
general characters as the female; and the tube functions both as 
germinal gland and receptacle for the sperm; the spermatozoa are 
very small granules, immense numbers of which are collected into 
one mass. No formation of spermatophores, or any copulatory organs 
have been detected. 

After referring to the musculature and the connective tissue, the 
author passes to the second part of his essay, where he deals with 
the classification of the Bopyride: owing to the small number of 
Species it is not necessary to form any subfamilies; the difficulties 
of definition lie in the fact that the form of the body, the number of 
antennary joints, and the arrangement of the gills differ so much in 
the two sexes. 


340 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Vermes. 


Peculiar mode of Copulation in Marine Dendrocela,*—Claparéde 
has already shown that in the genus T’hysanozoon there are two penes 
and two male genital orifices, but only one orifice in the female. This 
observation has not only been confirmed by A. Lang, but much ex- 
tended; he having found at Naples forms with nine or even fifteen penes. 
It is obvious that these could hardly have been intended to be intro- 
duced into the single vagina. The true signification of the contrivance 
was elucidated by the observation of the copulatory process in several 
species of Proceros—the penis was thrust indiscriminately into the 
body of the female, and through the wound thus formed the semen 
flowed into the oviduct which is distributed throughout the body. 
The female organ therefore serves only as an exit for the eggs. 


Classification of the Nematohelminthes.;—Dr. L. Orley pro- 
poses to establish three suborders, to which he would give the names 
of Nematentozoa, Rhabditiforme, and Anguillulide; the last are 
fitted for a free life, and are characterized therefore by the presence of 
circumoral bristles, lateral circular markings, and a caudal sucker ; 
the Rhabditiforme are intermediate, for, while they lack the charac- 
ters just mentioned, they resemble the free-living and differ from the 
parasitic Nematentozoa in having a thin cuticle, and a single straight 
tube, as well as in the fact that their nervous system is either entirely 
absent, or consists only ofa few fibres. So, again, while all Nematoids 
have free larve, those of the parasitic group perish unless they enter a 
host ; the Anguillulide do not so enter, but develope in mould or water, 
while the Rhabditide may or may not enter into hosts. There is an 
arrangement of the genera,.with short diagnoses, and two new species 
of Filaria, F. spiralis and F., ecaudata, are described. 


Relations of the Platyhelminthes{— Dr. A. Lang gives an 
account of the results to which he has been chiefly led by his 
study of Gunda segmentata.§ Considering first of all the Polyclades 
as creeping Ctenophores, he points out that, in his opinion, the 
Celoplana of Kowalevsky is not intermediate between the Ctenophora 
and Planaria, but is a true creeping Ctenophore; this form is remark- 
able for being flattened, for having the ctenophoral plates absent, and 
for a complete investment of cilia. The fact that external conditions 
can produce such great changes prevents us from giving any importance 
to such characters as these, when we compare the two groups. To 
most of the internal points of resemblance between them attention 
has already been directed ; but with regard to the development, we 
may note that Selenka has lately pointed out the striking similarity 
he has found in the earlier stages; and the observations of Lang 
are confirmatory of the fact that the embryo of the Polyclades 
is at first radial, and that it is only later that it becomes bilaterally 
symmetrical. 


* Arch. Sci. Phys. et Nat., vi. (1881) p. 308. 
+ Ann. and Mag. Nat. Hist., ix. (1882) pp. 301-18. 
+ Arch. de Biol., ii. pp. 533-52. 

§ Sce this Journal, ante, p. 197. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 341 


It is pointed out that G. segymentata presents many features of 
striking resemblance to certain Hirudinea, and especially the Rhyncob- 
dellide ; the pharynx, like that of the Triclades, is contained in a 
special cavity ; the intestine has always a number of paired diverticula, 
the number of which is constant for a given species. The two last 
are always longer than the others, and often have, on their outer 
side, secondary outgrowths. ‘These may be compared to the lateral 
and posterior branches of the intestine of the Triclades. The 
terminal intestine, the posterior dorsal anus, and the large sucker are 
to be regarded as formations special to the Hirudinea. 

There is likewise a considerable resemblance as regards the 
excretory system, but the collecting organ of the Hirudinea is, again, 
a new formation; in the adult leech there is no connection, as we 
know, between the excretory system and the enteric diverticula, but 
in the embryos of Clepsine there is evidence that this system is 
- developed from the epithelium of these diverticula. Striking resem- 
blances are also to be seen in the generative system. The ventral 
ganglionic chain of the Hirudinea does not appear to be so very 
different, if we suppose that it is comparable to the two longitudinal 
nerve-trunks of Gunda connected at segmental intervals by simple 
commissures. 

The musculature of the Hirudinea is mesenchymatous; the uni- 
cellular muscular fibres consist of an axial substance with a nucleus 
and a contractile sheath, just as in Guwnda there is a dorsal muscula- 
ture consisting of an external layer of transverse muscles, and an 
internal one of longitudinal fibres. In addition, there are dorso- 
ventral muscles which cannot be distinguished from the muscular 
dissepiments of Gunda, and, just as in that form, there is no enteric 
muscular layer. The body-cavity of the Hirudinea is not an entero- 
cole, but a schizoccele, formed by the vascular and lymphatic systems 
which are in communication with one another, and are developed, as 
Prof. Lankester has shown, by the liquefaction of the parenchymatous 
cells of the mesenchyma. Were the diverticula of the intestine to 
be detached from it, we should have a true enteroccele, which would 
then give rise to the epithelial musculature of the wall of the body 
and of the intestine, the excretory organs would thus acquire their 
primitive relations to the diverticula, and would serve, at the same 
time, for the evacuation of the generative products. It is probably 
along some such lines as these that the Oligochxta and Annelids 
have been developed from a Leech-like form. 

In connection with this subject Dr. C. Chun* points out that, 
though there are several points in common, there are also some 
important differences in the development of the Ctenophora and 
marine Planaria. In both there are four small and four large 
cleavage-spheres, and the gastrula is formed by epiboly. While, 
however, the rapidly multiplying small cells of the Ctenophora 
represent the rudiments of the ectoderm and mesoderm, in the 
Planaria there arise four primitive mesodermal cells, which alone 
form the mesoderm. He is not certain that the resemblances point 


* Biol. Centralbl., ii. (1882) pp. 5-16. 


342 SUMMARY OF CURRENT RESEARCHES RELATING TO 


to genetic relationships, and suggests that these observations may 
only be the commencement of the raising of a new set of problems. 


Entozoa confounded with Trichine.*—P. Mégnin points out that 
Trichina spiralis is not the only worm which may become encysted 
in the peritoneum or the muscles ; and after showing how various 
naturalists have been led to speak of Trichine where none exist, 
he gives an exact account of the character of T. spiralis. It is an 
extremely delicate, filiform worm, with a very narrow anterior 
extremity, in the centre of which is the small round mouth; the 
posterior end is truncated, and has the anus in its centre. The in- 
testinal tube is straight, and has a distinct cesophagus, stomach, and 
rectum. The agamic encysted forms are chiefly found in the 
muscles of animal life, but they are sometimes to be seen in the 
adipose tissue and in the muscles of the intestinal walls. Around 
the spherical space occupied by each coil, there is a deposit of 
colourless granular matter, which is more abundant towards the two 
poles, and has generally an elongated conical form. A single cyst 
or capsule rarely contains more than one worm. Later on, the walls 
of the cysts become incrusted with calcareous salts, within which 
the Trichina may continue to lie. After its death fatty degenera- 
tion occurs. 

The European mole is often in spring infested, on the external 
surface of its stomach and intestines, with small cysts, in which a 
worm is coiled up. The integument of this parasite is markedly 
striated, the mouth has a papilla, and the body is more cylindrical 
than that of Trichina; in addition to these and other characters 
there is a conical tail. This is the larval stage of Spiroptera strumosa. 
In some Spanish and other lizards there may often be found a 
number of cysts scattered throughout the body; here again the 
anatomical characters are those of Spiroptera rather than of Trichina ; 
and, in fact, the organism is S. abbreviata. Other forms from other 
animals, including the frog, are described ; one belongs to the genus 
Dispharagus, all the rest to Spiroptera. The author justly points out 
that a careful comparative study should be made on all occasions 
when it is stated, or believed by the observer, that he has to do with 
the genus Trichina. The paper will be very useful to all who are 
engaged in researches of this kind. 


Life-History of the Liver Fluke.|—Professor R. Leuckart states 
that his search for the young of Distomum hepaticum has at last 
been rewarded ; specimens of what he regarded as Limneus minutus 
were obtained from Dresden, and many of these were, after a few 
days, found to have in their respiratory cavity, and generally, near 
the kidney, a number of the embryos.with which he had in vain 
attempted to infect larger snails. More or less rounded bodies were 
found more or less closely packed together, and attached by a 
delicate cellular envelope to the operculum; there could be no doubt 
as to the relation of the parasite to the embryo, not only was there 


* Bull. Soc. Zool. France, v. (1881) pp. 189-98 (2 pls.). 
+ Arch, f. Naturgesch., xlviii. (1882) pp. 80-119 (1 pl). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 343 


the characteristic cephalic process, but the simple «-shaped eye-dot 
was converted into two irregular black dots, while the internal 
changes that were seen indicated a metamorphosis into the sporo- 
cyst stage. 

When the embryo escapes from its shell it contains all its germ- 
cells, which occupy the hinder portion of the body-cavity, while the 
anterior half is filled with a granular mass, which may be looked 
upou as the rudimentary enteron. At this stage the embryo has, in 
its general structure, so striking a resemblance to the Orthonectida 
of Giard, that the author is of opinion that these forms, just like the 
Dicyemidz, must be regarded as of the Trematode group; the fact 
that they never pass beyond an embryonic condition, even although 
they exhibit a complete differentiation of the sexes, need not cause 
much astonishment, if we reflect that the sexually mature entozoa 
of a large number of Invertebrates are, after all, to be morphologi- 
cally referred to more or less developed larval forms; in addition to 
this, we may note that there is not really the difference which there 
is ordinarily supposed to be between the germ-cells of the Trematoda 
and the female generative products. After swimming actively about 
for some time, the embryo makes its way into a snail, and generally 
into the respiratory cavity. As arule, the ciliated investment is now 
lost, and the two eyes become separated; the form of the body 
meanwhile ceases to be conical, and becomes more or less compressed. 
The loss of the cilia is, of course, the expression of the commence- 
ment of the parasitic life; before it begins the animal makes some 
powerful peristaltic movements, which loosen the cells. As soon as 
the animal has completely entered into a resting-period, a thin layer 
of clear cuticular substance is secreted around its outer surface ; this 
forms a kind of cyst, which is perfectly adapted to the form and 
changes in form of the body. Increase in size chiefly affects the 
germinal cells, some of which rapidly, and others less rapidly, divide 
repeatedly, and give rise to larger cell-aggregates; this growth leads 
to the enteron being pushed forwards, till it forms a kind of inner 
cap for the cephalic end of the body, the eyes become altered in 
position, and the number of the refractive granules increases. 

All the- germinal cells, however, do not undergo division and 
further development, a large number remain in their earlier con- 
dition; so again, during the first days of parasitic life, a number of 
sporocysts die down; some of those that become further developed 
would seem to have the power of dividing; at any rate the increase 
in the size of these parasites is less an active than a passive pheno- 
menon ; it is the consequence merely of the regular growth of the 
germ-spheres, which reacts on the form of the embryo; the walls of 
the body now become thicker, and lose largely their power of con- 
tractility; the ciliated funnels would seem to disappear, and even 
the eyes become obscured ; the last signs of the rudimentary enteron 
are now also lost. Some of the germ-spheres contained within the 
body begin to elongate, till they form tubes of some considerable size, 
presenting a specific internal and external organization and forming 
definite creatures. The inequality in the rate of development of the 


344 SUMMARY OF CURRENT RESEARCHES RELATING TO 


germs which was noted is now more distinctly manifested by the 
presence of organisms at very various stages of development. To the 
author’s great astonishment he, found that the products of the - 
sporocyst were not Distomata, but Rédie ; these, when free, are about 
0:4-0:7 mm. long, but are capable of considerable contraction and 
extension ; a head, median region, and tail-end may be distinguished ; 
the two former are separated sharply from one another by a prominent 
encircling ridge, while the body is distinguished from the tail by two 
blunt projecting processes, developed from the ventral surface. The 
tail is bluntly conical. The lips surrounding the mouth serve as 
attaching organs. The organization of the Kédia presents very con- 
siderable resemblance to that of the embryos, the organs being only 
more strongly individualized and the elementary parts more distinct, 
in correspondence with the larger body and higher function. The 
encircling ridge may be looked upon as a kind of skeletal girdle, 
which serves as the point of attachment for the retractors of the head 
and pharynx. As to the mode of development of this Rédia, the 
author believes that it passes through a gastrula stage; though some 
points were made out, the history of the germ-spheres could not be 
followed. Here then, unfortunately, this part of the history comes to 
an end; luckily some other snails were obtained in which were found 
three Rédiew; two of these contained Cercariz, but a third had a tail- 
less Distomum which is believed to have been a young D. hepaticum. 

In conclusion, some remarks are made on the small Lymneids 
which are believed to be the hosts. 


Excretory Apparatus of Turbellaria.* — In continuing his 
studies,t P. Francotte points out that Hallez denies the existence 
of the excretory canals in the genus Monocelis, while Schultze and 
others distinctly affirm their existence. The author has been able 
to confirm the latter doctrine, so far as it applies to the presence of 
these canals, but he has not been able to detect any communications 
with the outer world. On the other hand, he has discovered the pre- 
sence of ciliated terminal infundibula, very similar to those of the 
Trematoda and Cestoda. 

In dealing with the genus Monocelis, it is, first of all, necessary 
to take for examination perfectly fresh specimens; there will then be 
seen a system of principal canals, fine secondary canaliculi which 
form a plexus throughout the whole, and vibratile infundibula united 
to the plexus by a canal. There are two pairs of principal canals on 
either side of the middle line, two external and two internal ; these 
are united with one another by several anastomoses of the same size; 
the distinct walls are transparent and very hyaline, but no definite 
histological structure could be made out. At certain points there 
may be seen a long conical filiform cilium; the canals contain a 
transparent liquid in which are some small granulations. The secondary 
canaliculi arise from the ciliated infundibula and have a very delicate 
wall, of no distinct structure; they are best made out in the anterior 


* Bull. Acad. R. Belg., iii. (1882) pp. 88-98. 
¢ See this Journal, i. (1881) p. 460. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 345 


region; the infundibula are conical, and have, in optical section, a 
triangular form; the wall is here again transparent and hyaline. It 
is interesting and important to note that in sections of these worms, 
though prepared by different methods, no trace of the existing canals 
has yet been detected. 

The Dendroceela (as represented by Polyceelis nigra) would appear 
to be without the secondary canaliculi, the infundibula being connected 
with the principal by five canals. The principal canals here form a 
plexus and would seem to open to the exterior ; the highly refractive 
wall here again appears to be without any definite structure. Through- 
out their whole extent there is a continuous vibratile line lining the 
canals. The infundibula are conical and their wall is formed by the 
walls of the canals into which they open, but the black pigment of 
the form examined prevented the author from seeing whether or not 
the canals are completely closed. 


New Parasites.*—J. Fraipont describes some parasites of Uro- 
mastia acanthinurus. Only five Tenie are yet known from any of the 
Saurians; the new form, 7’. alata, has two aliform delicate expansions 
on the neck ; the transparency of the joints allows of the easy detection 
of the two pairs of longitudinal canals belonging to the excretory 
system, which extend throughout the whole of the body. In the 
terminal segments there were detected a considerable number of eggs, 
with a thin but resistent membrane, and each containing a hexacanth 
embryo, surrounded by an embryonic envelope. 

The presence of an Echinorhynchus is interesting as, apparently, no 
species of the genus has ever yet been found in a Saurian; the present 
species is called EH. uromasticis. Filaria candazei is a new species 
found in the subcutaneous connective tissue and between the different 
muscles of the body; the female is much larger and longer than the 
male (100-120 mm.). The muscles are arranged on the poly- 
myarian type. Special organs in the shape of four pairs of pediculated 
appendages bearing each two small papilliform growths on their free 
end, are arranged symmetrically on either side of the sheath of 
the penis. 


Tube of Stephanoceros Eichornii.t—Mr. T. B. Rosseter, on sever- 
ing the longitudinal muscles that extend down the peduncle (cutting 
the tail through close to the base), saw the Stephanoceros swim out of 
the tube at the oral orifice, leaving it intact, and thus confirming the 
view of Mr. Slack, as against that of Mr. Pritchard, that it is tubular 
and nota solid gelatinous mass. He considers it clear that “itis per- 
fectly hollow : there is no attachment between the cell and the creature, 
and it is quite as independent of its cell as Melicerta ringens is of its 
cell.” The dragging down of the upper portion of the tube is caused 
by the teeth of the tentacles overlapping the sides and not from 
attachment to the neck of the creature. 

Mr. J. Badcock, however, considers that both parties are right in 


* Bull. R. Acad. Belg., li. (1882) pp. 99-106. 
+ Sci.-Gossip, 1881, pp. 107-9 (6 figs.). 
Ser. 2.—Vou. IL. 2A 


346 SUMMARY OF CURRENT RESEARCHES RELATING TO 


the view they have taken; for, as the result of his own observations, 
he finds that when young the tube is hollow, but when old the cavity 
becomes filled up with a mucous substance. 


Echinodermata. 


Structure of Pedicellarie.*—A. Foettinger has examined the 
gemmiform pedicellarie of Spherechinus granularis. He finds that 
the three more or less ovoid glandular sacs which are formed on 
the stalks of these, are surrounded by the common epithelial mem- 
brane which invests the whole of the organ. They open to the 
exterior by an orifice at their superior extremity, and they alternate 
in position with the valves which form the head of the pedicellaria. 

After decalcification by means of chromic acid, and staining with 
carmine, the following tissues can be seen on making a transverse 
section of a pedicellaria at the level of these glands; there is an 
external epithelium, containing a large number of pigment-corpuscles, 
a layer of connective fibrille which separates and unites the glan- 
dular sacs; these have an external layer of flattened muscular fibres, 
with an oval nucleus, and these fibres are arranged concentrically 
around the orifice of the gland ; the contents of the sac vary greatly, 
being in some cases formed of a granular, and probably mucous, 
matter which contains refractive corpuscles which swell up under the 
action of water, and are, doubtless, modified nuclei; in other cases 
the substance is filamentous, but this is ascribed to the coagulating 
action of alcohol; this substance swells up considerably on contact 
with water, &c.; and this increase in volume, when it happens with an 
uninjured pedicellaria, must lead to the outpouring of the contamed 
mucus. When certain transverse sections are made, the contents of 
the sac are seen to be constituted almost solely of protoplasm with 
nuclei and cell-walls more or less intact. In longitudinal sections 
some of the glands present a protoplasmic layer investing the base 
and the walls. The author would explain these facts by considering 
that the glandular sacs are primitively filled by a tissue formed of 
polyhedral cells, and making a compact mass. At a certain time 
these cells are converted into mucus, and this change goes on until 
all the external cells are affected by it. 

The three valves which form the head of the gemmiform pedi- 
cellaria are pyriform in profile view, and ovoid from in front; the enve- 
loping layer is merely epithelium ; below it there is a layer of granular 
and fibrillar connective tissue, which is generally very delicate, but is 
abundant between the valves, and near their upper surface. Beneath 
this tissue we find a glandular sac, which is double above; at the peri- 
pheral extremity the two branches unite into a single canal. ‘This 
glandular sac would also seem to have its primitive contents formed 
of a compact cellular tissue. Hchinus melo and Echinometra subangu- 
laris have at the base of the head of their pedicellarie organs which 
are very probably homologous with those found on the stalk of S. 
granularis. M. Foettinger has also examined the pedicellarie of 


* Arch. de Biol., ii. (1881) pp. 455-96 (3 pls.). Bull. Acad. R. Belg., ii. (1881) 
pp. 493-504. : 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 347 


Diadema setosum and D. mexicanum ; these, which are about 2 mm. 
long, are club-shaped and end in a very short and delicate pedicle ; 
they enclose three large elongated glands with an orifice at their 
upper end; the glands are closely applied to one another, but have 
superiorly, where they diminish in size, six separating cavities which 
may be looked on as the homologue of the head of the pedicellariz of 
S. granularis. In Mespilia globulus the pedicellarie are excessively 
small and very numerous. In Strongylocentrotus lividus and S. dro- 
bachiensis the gemmiform pedicellariz have a stalk which has consi- 
derable resemblance to that of the ophiocephalous and tridactyle 
pedicellarie. When we compare S. granularis with Echinometra and 
Diadema we find that in the first the glands and head are equally 
developed, that in the second the glands are rudimentary, and that 
in the third it is the head which is rudimentary. 

The author, not having been able to make any original observa- 
tions on living forms, accepts the views of Sladen, who was the first 
to direct pointed attention to this subject. 


Circulating Apparatus of Starfishes.*—E. Perrier and J. Poirier, 
after noticing the accounts of earlier observers, in which there is a 
large amount of very perplexing contradiction, state that they find 
that the vascular apparatus described by Ludwig in the partition of 
the infrabrachial canals has no existence, that the partition is not 
continuous, but that it is reduced at certain points to a vertical 
lamella while at others it presents distinct foramina. The body 
adherent to the hydrophoral canal, where Ludwig sees a plexus of 
vessels and which he regards as being the heart, is (as Jourdain 
showed in 1867) nothing but a gland; the same has been shown to be 
the case in the common sea-urchin, and Koehler has found the same 
to be true for the Spatangide. As the Ophiuroidea present a similar 
structure, we may say that, in all Echinoderms, this so-called heart 
is a simple gland. 

The system of lateral branches described by Hoffmann as arising 
from the infrabrachial canals, has been detected, but a different 
account is given of its relations. These lateral branches do not 
curve round the ambulacral pore, but pass straight to the edge of the 
ambulacral groove; what Hoffmann took for the second branch of 
the horse-shoe is a fresh canal, independent of and identical with 
the first; and these two canals pass, parallel to one another, to 
the edge of the arm; there they bifurcate and the two neighbouring 
branches together pass through a foramen between two contiguous 
ambulacral, and the adjacent adambulacral pieces. In these foramina 
the two branches unite to form a common branch, which opens 
directly into the general cavity. There is always a similar hole 
between two contiguous ambulacral pieces, so that the infrabra- 
chial canals always communicate with the general cavity by as many 
holes as there are ambulacral pieces. The infrabrachial canals and 
the branches which they give off are, therefore, merely dependences 
of the general cavity, divided into two communicating parts by the 


* Comptes Rendus, xciy. (1882) pp. 658-61. : - 
Ly, Beg 


348 SUMMARY OF CURRENT RESEARCHES RELATING TO 


tentacular canals, and the system of ambulacral pieces. These canals 
also present a mode of partition which is remarkably like what is 
found in the brachial cavity of the Comatule; this mode is alone 
found somewhat late in the Crinoids, and we see that there is, there- 
fore, in them “an accidental character” which contrasts strongly with 
the almost absolute fixity of the relations of the ambulacral appa- 
ratus. “This last is the essential and dominant character in the 
organization of an Echinoderm.” The authors also find that the 
integument of the infrabrachial canals is formed of small bipolar 
cells, the swollen portions of which are near the external surface. 


Genital Passages of Asterias.*—S. Jourdain describes the pre- 
sence of five vasculiform ducts, lying below and applied to the 
internal face of the dorsal integument, the sides of which form a 
pentagon. The angles of the pentagon point to the interradial septa, 
and a vessel, embracing each septum, establishes a continuity between 
the branches which correspond to the sides of the pentagon. This 
vasculiform pentagon was regarded by Tiedemann as a dorsal venous 
circle, but from each septum there are given off two branches which 
become connected with the appended genital glands, and they are the 
only ones which are given off from it. The author is of opinion that 
this pentagon has no relation to the proper vascular system. The 
vessels do not have the relations of blood-vessels, but they are in 
communication with the interior of the gland and its diverticula; in 
other words, they are disposed as the excretory canals. The vasculi- 
form dorsal plexus varies in size with the activity of the genital 
glands, and its walls are provided with muscles, while the internal 
ciliated surface has a projecting fold of glandular tissue. At the 
point of attachment of the enlarged interradial septum, which corre- 
sponds to the madreporic plate, the ducts of the pentagon open into an 
elongated fusiform sac, which is invested in an elastic membrane 
containing muscular fibres. At the extremity of this sac there are two 
brownish pyriform bodies, which are in connection with the canals of 
the pentagon ; these, with the sac and its projection, are what most 
writers have considered to be the heart. They are not so, but merely 
dilated continuations of the pentagon. The fusiform sac opens into 
a circum-oral ring, to which are attached small paired globular bodies, 
almost similar in histological structure to the pyriform bodies. An 
orifice, of extremely small size, and very difficult to detect, is to be 
found where the sac is continuous with the circum-oral ring; so that, 
Asterias, just as in Holothurians, the sperm and the ova are passed to 
the exterior by a pore in the circum-oral circlet, and not by interradial 
perforated plates. 

E. Perrier and J. Poirier state,t however, that specimens of 
Asterias glacialis, alive and depositing ova, are seen to have their ova 
escaping by ten groups of small holes, set a little above each inter- 
radial angle ; each group contains three to six orifices; in specimens 
that had been opened from the dorsal surface no ova were to be found 


* Comptes Rendus, xciy. (1882) pp. 744-6. 
t Ibid., pp. 891-2, 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 349 


in the circular dorsal canal, or in the tubular pouch surrounding the 
hydrophoral canal; this pouch serves as a means of communication 
between the dorsal and ventral circular canals, and is really nothing 
more than one of the spaces formed by the peritoneal membrane, and 
enlarged ; but neither it nor the dorsal canal have anything to do 
with the excretory apparatus of the generative system. 


Celenterata. 


Clavularia prolifera.*—After a description of this new Alcyon- 
arian, G. v. Koch discusses the mode of connection of the buds with the 
trunk ; he points out that it is a remarkable fact that these buds are 
' not mere outpushings of the body-wall of the mother-polyps, but that 
at the base of each bud there is a canalicular network in the thickened 
connective substance of the mother, by which the two polyp-cavities 
indirectly communicate with one another. Discussing the question 
of its origin; the author shows that, if it is secondary, or if, in other 
words, the young polyp first developes as a simple evagination, and 
gives rise to the plexus by a partial fusion of the intermediate sub- 
stance, it would bea structure which owed its existence to adapta- 
tion, or had only a physiological significance, such as might be 
explained as due to the more or less complete isolation of the polyps. 
On the other hand, if it is primary, or, if it gave rise to the young 
bud, then we should have to seek its morphological significance, and 
might compare this canalicular network with the nutrient canals of 
the Gorgonida. 

This important question could not be decided on the preserved 
specimen which the author has-examined, but a study of some allied 
forms shows that in this group of corals the digestive cavities of 
the buds never open directly into that of the mother, and that 
there are a series of intermediate stages from those in which the 
polyp-buds are derived from simple stoions, and those in which the 
stolons form canals in the thickened mesoderm, and those, lastly, 
in which the thin partition between the bud and the mother is per- 
forated by small orifices. We may therefore conclude that the more 
or less incomplete separation seen in the Alcyonaria has a certain use, 
and that it is not an adaptive arrangement, but one which may be 
referred to the formation of the stolons; the canalicular network in 
the mesoderm of the mother-polyps, which lies at the base of the 
buds and connects them with the mother, is a stolon-formation (in 
its widest sense). And, further, we find that in the Alcyonaria 
asexual reproduction is never effected by division or direct gemma- 
tion, but always indirectly, or by stolons or structures homologous 
therewith. 

A study of the new species throws some light on the horny sheaths 
of the spicules, and their relations to the ectoderm, for we find 
that the younger spicules are always invested in a protoplasmic 
nucleated sheath, which may also be frequently made out in older 
examples, where we find cells connected by pairs and having within 


* Morph. Jahrbuch, vii. (1881) pp. 467-87 (2 pls.). 


350 SUMMARY OF CURRENT RESEARCHES RELATING TO 


them the young spicule. The doctrine, then, of Kowalevsky, that the 
spicules arise from cellular elements, may probably be extended to 
all the Alcyonarians. And the same would seem to hold for the 
horny sheaths. These cells found in the mesoderm would seem to 
have been derived from the ectoderm, whence cells have been observed 
to wander into the middle layer ; as this has never been noted with 
regard to the endodermal cells, we may conclude that the hard skeletal 
parts of the Alcyonaria, whether spicula or horny sheaths, are 
derived from the ectoderm. 


Porifera. 


Sponges of the Gulf of Triest.*—In his seccnd paper on the 
marine fauna of the Gulf of Triest, Dr. E. Graeffe deals with 
the Spongiarie; with which O. Schmidt has already dealt. It 
is pointed out that sponges have but few enemies; some of the 
species of Doris, Doriopsis, and Fissurella attack their outer layers ; 
on the other hand, they have a number of parasites, Algw and 
Chetopod Annelids being the most conspicuous. Gammarida are 
also not unfrequently found. Some silicious sponges have their 
outer surface affected by small Aphroditeide and by Hydroid 
Polyps. 

i the list given by the author especial attention is directed to 
the places in which they are found, and their time of reproduction, 
with some notes on the localities of the ova and larve. 


Spongiophaga in Fresh-water Sponges.t—Mr. E. Potts insists 
that Mr. Carter is mistaken in considering that the slender curling or 
twisted tendrils { of the statosphere of fresh-water sponges of the 
genus Carterel’a § are parasites, as described by him under the name 
of Spongiophaga Pottsi.|| Prof. Leidy, by whom they were examined, 
says that “ there can be no question as to the tendrils being part of 
the structure of the statoblast—homogeneous extensions of its inner 
capsule.” 

The function of the tendrils is apparently to meet the emergency 
occasioned by the looseness of the skeleton structure, from which 
the sarcode-flesh dying early washes away, most of the spicules soon 
following in the winter floods. The eggs are thus left to the pro- 
tection of the tendrils, which lap them together, bind them to the 
remaining spicules or the roots of water-weeds or shore plants, or 
assuming the réle of the hair which the plasterer uses, bind the 
deposited silt about them, and both to the stones, where they await the 
appointed time for a new growth. The resemblance in material 
structure of these tendrils to that of the specialized hooks of some of 
the Polyzoa is very striking. 

Mr. Carter, as the result of subsequent examinations,f agrees with 
Mr. Potts’ view as to the filaments being in reality cirrous appendages 
on the statoblasts and not Spongiophaga. 

* Claus’ Arbeit., iv. (1882) pp. 313-21. 

t Proc. Acad. Nat. Sci. Philad., 1881, pp. 460-3. 
t See this Journal, i. (1881) p. 613. 

§ Ibid., p. 901. || Ibid., p. 901. 

4 Ann. and Mag. Nat. Hist., ix. (1882) pp. 390-6. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 351 


New Fresh-water Sponges.*—Mr. E. Potts describes three 
more curious fresh-water sponges. One (Meyenia crateriforma) is 
of a very delicate structure ; its framework of skeleton spicules is 
exceedingly meagre, and slightly bound together, scarcely amounting 
to a mesh system, and the numerous small white statospheres are 
found in recesses far larger than themselves. Another (Heteromeyenia 
ryderii) forms beautiful green masses, often four to five inches in 
diameter, and about a quarter of an inch in thickness. The surface 
is irregular, occasionally rising into rounded lobes; the efferent 
canals are deeply channelled in the upper surface of the sponge, five 
or six sometimes converging to a common orifice. The statospheres 
are numerous and rather small. There are two series of birotulate 
spicules. The third species belongs to the genus Tubella. This 
genus, established by Carter, contained only four species, all from the 
Amazon river. The new species is small, encrusting, and has been 
named TJ. pennsylvanica. The skeleton spicules are arranged in a 
simple series of single non-fasciculated spicules, in the interspaces of 
which the statospheres are abundant. These spicules are very vari- 
able in size and shape, but all are entirely and coarsely spined. The 
dermal spicules seem absent. 


Protozoa. 


Organization of the Cilio-flagellata.t—R. S. Bergh gives an 
account of the Cilio-flagellata observed in the Little Belt and in the 
fresh waters of Denmark; the first part containing “ History” and 
“ Bibliography,” the second a description of ten genera and twenty 
species, and the third Phylogeny. ‘The chemical composition of the 
various parts of the body is fully dealt with so far as that is possible 
by the use of reagents, as well as the anatomical structure. Seventy- 
three figures show what great variation is presented by certain forms, 
and how difficult it often is to define the limits of the species. 

The body of all Cilio-flagellata is bilaterally asymmetrical, 
differing remarkably, however, in the various representatives ; some- 
times it is compressed from front to back (Diplopsalis lenticula, 
Glenodinium Warmingii), sometimes from above downwards (Ceratium, 
Peridinium), and sometimes laterally (Dinophysis, Amphidinium, Pro- 
rocentrum). It may be drawn out into horns (Ceratium, Peridinium 
divergens) or may be destitute of any. 

They possess either a lorica (cell-membrane) (Ceratium, Proto- 
ceratium, Peridinium, Protoperidinium, Dinophysis, Diplopsalis, Gleno- 
dinium, Prorocentrum), or are naked (Gymnodinium, Polykrikos). The 
membrane consists either of cellulose or a similar hydro-carbon, and is 
coloured by chlor-iodide of zinc, pale violet (Ceratium, Perid. tabu- 
latum) or intense red (Perid. divergens, Protoperidinium, Diplopsalis), or 
even pale red (Prorocentrum, Glenodinium cinctum). Those forms 
which have been closely examined do not contain silica. The more 
minute structure of the cell-membrane varies much; it is either 
transparent and structureless (Glenodinium) or ornamented with 


* Proc. Acad. Nat. Sci. Phila., 1882, p. 12. 
+ Morph. Jahrbuch, vii. (1881) pp. 177-288 (5 pls. and 1 fig.). 


352. SUMMARY OF CURRENT RESEARCHES RELATING TO 


reticulately arranged ridges (Ceratium cornutum, and C. hirundinella, 
Dinophysis), or the ridges do not form a network, but run more 
irregularly, pores also appearing (Ceratium tripos, C. furca, C. fusus) ; 
finally we find a division by bands into a number of plates of various 
sizes with smaller intermediate strie#, so that the plates show the 
reticulated structure, the bands on the contrary being transversely 
marked (Peridinium, Protoperidinium, Diplopsalis) ; in Prorocentrum 
(apparently) the membrane consists of two cuirasses, which are 
perforated with fine pores. 

The protoplasm is apparently always separated into ectoplasm and 
endoplasm, which both show very varying differentiation. In the 
cuirassed forms the ectoplasm is always quite structureless and homo- 
geneous ; in Gymnodinium and Polykrikos, the most highly developed 
forms, it shows many peculiarities; in G. gracile it is very much 
wrinkled and folded, and in G. spirale it contains muscular fibrille 
in its inner layers ; in Polykrikos trichocysts are developed in it. The 
endoplasm sometimes contains, at the same time, chlorophyll, and 
diatomin and starch, or some similar amylaceous matter (Ceratiwm, 
Protoceratium, Perid. tabulatum, Protoperid. Michaelis, Glenodinium, 
Dinophysis acuta, Prorocentrum), which indicates a mode of nutrition 
similar to that of plants; sometimes these substances are wanting, 
and the body contains digested organisms (Gymnodinium, Polykrikos), 
which indicates that alimentation takes place as in animals; finally, 
there seem to be some forms which are nourished neither by the 
agency of chlorophyll (the assimilation of carbonic acid) nor by 
animal matter, as we find in their endoplasm neither the above- 
mentioned colouring matter nor foreign organisms (as in Protoperid. 
pellucidum, Perid. divergens, Diplopsalis lenticula, Dinophysis levis). 
The endoplasm in Perid. divergens, Diplopsalis lenticula, &e., is 
coloured slightly red ; in the former it usually contains little drops of 
red-coloured oil. No contractile vesicle can be pointed out with 
certainty. In all the forms in which the nutrition could not be seen 
to be either assimilative or purely animal, a vesicle is found which 
often communicates with the outer world through the flagellum- 
furrow and a narrow canal, but is sometimes separated from it; 
probably its function is to take in sea-water (with nourishment). 

The nucleus is generally single; only in Polykrikos we find four 
(larger) nuclei. Those of the Dinifera consist of a fine granular 
substance containing no nucleoli and colouring bright pink when 
treated with picrocarmine (after alcohol). Only in Polykrikos is 
there found a second sort of smaller nucleus (perhaps “ primary 
nucleus” in the same sense as in the Ciliata), The nucleus of 
Prorocentrum still needs a closer examination. 

The locomotor apparatus, the special characteristic of the Cilio- 
flagellata, consists of long, powerful flagella and smaller cilia. These 
cilia spring either directly from the anterior end of the body (Proro- 
centrum), or are arranged in one or two contractile rows in a transverse 
furrow formed by two projecting plates or ridges (Dinifera). The 
furrow lies either at the anterior extremity of the body (Dinophysis, 
Amphidinium), or about the middle (the other forms) ; in Gymnodinium 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 3593 


spirale it is spirally twisted. The ciliary movement seems to go in one 
constant direction, beginning on the left of the ventral surface. In 
Gymnodinium there appears to be only one contractile row in the 
furrow. In Polykrikos there are eight furrows independent of each 
other. The edges of these furrows are interrupted on the ventral side ; 
the posterior ones continue in a peculiar system of horns and ridges, 
which are either placed close on each other, as on the small ventral 
side of Dinophysis, or are separated from each other as a right and 
left hand division (Protoperidinium) ; this entire apparatus serves for 
limiting the longitudinal furrow. In the other forms either the 
horns alone persist (Peridinium), or the ridges (Diplopsalis, Gleno- 
dinium), or both are absent (Ceratium, Gymnodinium.) The Flagellum 
is inserted either through a wide ventral aperture in the membrane 
(Ceratium) or through a narrow fissure in the longitudinal furrow, 
either at the anterior pole (Prorocentrum) or the posterior pole 
(Amphidinium, according to Claparéde and Lachmann) or in their 
neighbourhood. 

Of the propagation and development of the Cilio-flagellata little is 
known with certainty. We find fission as well as conjugation. 
Transverse fission results either in a free-swimming animalcule (as 
for example in Polykrikos, in Allman’s Perid. uberrimum), or in with- 
drawal into the old membrane (Perid. tabulatum), or finally in certain 
eysts, which are either round (Glenodinium cinctum, Gymnodinium 
according to Stein) or have peculiar, strange (horned) forms (Perid. 
tabulatum according to Stein). Conjugation is especially shown by 
Stein in Gymnodinium pulvisculus ; but several of his statements, the 
author thinks, require a complete revision. - 

Under the head of “ Phylogeny ” the author endeavours to unravel 
the relationship of the organisms, even for each genus and species. 
The results of such an attempt could not be very definite, for, as he 
himself says, we have not the necessary paleontological evidences and 
consequently the intermediate forms are wanting that have existed in 
past times. The author’s six genealogical trees can therefore only be 
taken for what they are worth, that is as a representation of the more 
or less intimate relation which we can recognize between certain 
forms. It is, however, a clever and convenient method of expressing 
one’s views of the affinities.* 

According to the author, the Flagellata form a point of departure 
from which are developed phylogenetically (diverging on different 
sides), the Noctiluce, Rhizopoda and Cilio-flagellata. The oldest 
forms of Cilio-flagellata were the Adinida, of which only one living 
species (Prorocentrum) isnow known. ‘They acquired small cilia, and 
a bilaterally asymmetrical form. There later appeared the ciliary 
apparatus, at first posteriorly and then anteriorly limited by the 
ridges of the membrane, so that a transverse furrow was formed 
(Dinifera) which was originally on the anterior margin (Dinophysis, 
Amphidinium) ; then the flagellum was removed from its primary 
position posteriorly, whereby a longitudinal furrow was formed, at 
first confined by a complicated apparatus of ridges and horns. Still 


* Cf, Arch, Sci. Phys. et Nat., vi. (1881) pp. 402-4. 


354 SUMMARY OF CURRENT RESEARCHES RELATING TO 


later the body became rounded, the transverse furrow moved in a 
posterior direction, and the membrane acquired plates, whilst the lon- 
gitudinal furrow-apparatus remained entire (Protoperidinium). From 
this point began the development in two directions, since on one 
side the ridges (Peridinium, Protoceratium, Ceratium) and on the 
other the horn-like processes of the longitudinal furrow (Diplopsaria, 
Glenodinium) were reduced, and finally the plates coalesced. The 
highest division is represented by the Gymnodinida in which sub- 
family the membrane is quite abolished, and numerous differentia- 
tions of the protoplasm developed. Finally, springing from these, 
are forms in which the flagellum is reduced, but in which a cytostom 
and cytopyge are differentiated in order to give origin to the Peri- 
tricha, the oldest ciliated Infusoria (Mesodinium). 

L. Maggi* establishes the occurrence of Ceratium furca Ehrenberg, 
hitherto almost exclusively known as marine, in certain lakes of Upper 
Italy (Lago di Candia, near Ivrea, and Lago di Annone, in Brianza) ; 
at the same time he devotes much attention to the synonymy of this 
species and to the history of the investigations into the phosphorescent 
powers of the Ceratia. Like Claparéde and Lachmann, he regards 
Peridinium lineatum as identical with Ceratium furca. The form was 
not observed alive, but only the remains of its tests; among these 
occurred in the Lago di Candia, a considerable number somewhat 
differently shaped, which the author thinks right to constitute a special 
variety, under the name lacustris. 

The same writer f gives a list of all the Cilio-flagellata known to 
him through literature or by original observation, adding the syn- 
onyms and habitats of each form. He retains the following five 
genera :—Ceratium (with seventeen species, two of which are fossil), 
Peridinium (with thirty species, all recent, two fossil ones also occur), 
Dinophysis (seven species ), Amphidinium (one species) and Prorocentrum 
(one species). He believes that Claparéde and Lachmann have gone 
too far in their reduction of the number of the species, and have 
allowed themselves to be guided by reasons which will not bear in- 
vestigation. He endeavours to show here, as in another place, that 
the Cilio-flagellata were originally derived from the sea, in which even 
at the present time they attain so great an importance, and have only 
later extended into fresh water. By this means the circumstance is 
explained of their inhabiting more particularly the larger fresh-water 
lakes, for in these are found conditions resembling to a certain extent 
those of the sea. On this view Prof. O. Biitschlit remarks that the author 
has not paid attention to Stein’s writings on the Cilio-flagellata, or 
he would have seen that Stein distinguishes three additional genera, 
Gymnodinium, Hemidinium, and Glenodinium, but is inclined to remove 
the genus Prorocentrum from the group. 

L. Maggi § further arranges together all the Cilio-flagellata known 

* Bollet. Scientif., i. (1880) pp. 125-8. Cf. Zool. Jahresber. Neapel for 
1880, i. p. 167. 

+ Op. cit., ii. (1880) pp. 7-16. Cf. tom. cit., p. 167, 

+ Tom. cit., p. 167. 

§ Rendic. R. Istit. Lombard. xiii. (1880) p. 20. Cf. Zool. Jahresber. Neapel, 
tom. cit., pp. 167-8. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 350 


to him through the literature of the subject, according to their mode 
of occurrence. Thus the forms hitherto found in the different seas 
are enumerated, after which a catalogue is given of those belonging to 
fresh water, according to the manner of their occurrence in lakes, 
marshes, streams, ditches, &c.; and finally a list of those forms which 
have been hitherto found in both sea and fresh water. These last 
include four forms, viz. Ceratium tripos Ehrb., furca Ehrb., Peridinium 
spiniferum Clap. and Lachm. (according to Maggi’s observations), and 
Prorocentrum micans Ehrb. The paper concludes with an enume- 
ration of the known fresh-water forms, arranged according to the 
different countries in which they occur, and going so far as to give 
for each form the particular locality in which observers had met 
with it. From this section may be specially selected the fact that 
the author records Peridinium pulvisculus, KEhrb., spiniferum Clap. 
and Lachm., tabulatum Schm., as well as Ceratiwm longicorne Perty, 
as found by him in Upper Italy. It is unnecessary to go more fully 
into Maggi’s results, as he has made no attempt to examine closely 
and compare the forms described by various writers, in order to 
decide their claims, but contents himself with simply enumerating 
them. 


Infusorian with Spicular Skeleton.*—R. S. Bergh has obtained 
large quantities of the Infusorian described by Claparéde and Lach- 
mann under the name Coleps fusus, in the open sea off the Small 
‘Belt (Denmark). The peculiarities which he has observed in this 
Species appear to him sufficient to raise it to the rank of a new 
genus, whose principal character, distinguishing it from Coleps, is 
that the skeletal sheath is not a continuous fenestrated test, but con- 
sists of single disconnected spicules. These are parallel to the long 
axis of the animal, which has a considerable longitudinal extension 
and is pointed at the aboral pole; they are arranged in five 
transverse series, showing considerable differences between their 
heights. The spicules are provided with short lateral cross-branches, 
differing (but not constantly so) in number in the different series; they 
constitute an indication of reticulate structure, but, as already stated, 
they are not so much developed as to unite the spicules together. 
The spicule-elements of the skeleton consist of an organic sub- 
stance, and lie imbedded in the peripheral protoplasmic layer. The 
cilia are placed above, not between them. A compact crown of cilia 
is found at the oral pole. The simple, roundish nucleus lies within 
the middle series of spicules. 


Contractile Vacuole of Vorticella.t—After an historical intro- 
duction relating to the controversy about the presence of a membrane to 
the contractile chamber, J. Limbach describes his own observations 
on the subject as follows:—In pathologically altered specimens of 
Vorticelle, in which their characteristic ciliated organ is swollen up 
and the body is detached from the pedicel, the contractile vacuole 

* Vidensk. Meddel. Naturh. Foren. Copenhagen, 1879-80, pp. 265-70, wood- 
cuts. Cf. Zool. Jahresber. Neapel for 1880, i. p. 170. 


+ Kosmos, (Zeitschr. poln. Naturf. Ges. Kopernicus), 1880, pp. 213-21. Cf. 
Zool, Jahresber. Neapel for 1880, i. p. 169. 


356 SUMMARY OF CURRENT RESEARCHES RELATING TO 


becomes more and more distended, so as to include as much as three- 
fourths of the breadth of the body. It is scarcely probable that an 
unusually thin membrane in connection with the vacuole, if present, 
should be able to stretch to such an extent, without bursting, a con- 
sideration which appears to furnish additional evidence in favour of 
the absence of a membranous wall in the vacuole. Limbach, by 
observation of Vorticella cyathina during fission, has been able to 
determine the opening of the vacuole into the vestibule, and the 
expulsion of its liquid through the opening of the latter. The same 
results were obtained from the abnormal Vorticelle above mentioned. 
Thus the contractile vacuole constitutes an excretory organ, although 
it may at the same time assist in the function of respiration. 


Geographical Distribution of Rhizopoda.*—C. Parona gives a 
review of the Rhizopoda found by Leidy in North America, of those 
met with at the same time in Europe, and finally of those found since 
then in Italy. The astonishing agreement in the Protozoan faunas 
of districts so widely separated prompts him to raise the question 
whether the laws of phylogenetic development are hereby modified, a 
question which he answers negatively. This agreement is explained, 
according to his view, by the original derivation of the Protozoan 
faunas of both regions from a common source, and this must un- 
doubtedly have been a marine source.t| The closely similar alter- 
ations which have taken place in the circumstances and manner of 
life which the primitive Protista-faunas of the two continents have 
undergone in the course of ages, are considered by the author to have 
gone so far as to cause even the development of closely similar forms. 
He is therefore inclined, at any rate in this case, to admit a poly- 
phyletic origin of species. 

Classification of the Gregarinida.{—B. Gabriel puts forward in 
two places a new classification of this group, based on his investiga- 
tions into the process of reproduction in the Gregarines. He has 
been led to take this course by finding the principles advanced up 
to the present time by Stein and Schneider, and depending essentially 
upon the morphological peculiarities of the mature forms, to be in- 
sufficient ; he therefore believes that a classification can only be based 
on the reproductive relations of these organisms. The presence or 
absence of a septum (the point of distinction between Mono- and 
Polycystide of Stein and Schneider) has in his eyes no deep im- 
portance, inasmuch as he has found at Naples, in Typton spongicola, 
a Gregarine, which in its early life is a septum-less Monocystidean, 
but acquires later not only one, but numerous transverse septa, and 
thus presents a colonial or strobila-form which arises by terminal 
budding, and whose segments are individually capable of in- 
_dependent reproduction. Gabriel finds the attaching apparatus of 


* Bollet. Scientif., ii. (1880) pp. 43-50. Cf. Zool. Jahresber. Neapel for 
1880, i. p. 127. 

+ Prof. O. Biitschli (loc. cit.) remarks on this that this opinion might be ex- 
tended with probable accuracy to all fresh-water faunas. 

¢ Ber, Versamml. deutsch. Naturforscher u. Aerzte, 1880, pp. 82-3. Cf. Zool. 
Jahresber, Neapel for 1880, i. pp. 160-1. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 357 


the Polycystides to have no greater importance, it being found 
similarly developed in Monocystideew as well. The method of 
generation and development exhibits important variations both in 
the Mono- and Polycystidex, and, indeed, is repeatedly found to be 
identical in members of both the groups. The author at first con- 
sidered that the Gregarines should be broken up into two subdivisions, 
according as encystation occurs in the course of reproduction or does 
not ; these were termed respectively Acystoplasta and Cystoplasta. He 
even found that in a Gregarine obtained from Julus sabulosus (and 
probably identical with Stenocephalus Juli Schn.), the spore-formation 
was completed without encystation, and without alteration of any 
kind in the shape of the body. He considers, however, this case not 
of sufficient importance to establish the above two subdivisions, and 
therefore distinguishes three divisions by the process of development 
and spore-formation ; their characters may, however, be stated at the 
outset as difficult to understand, owing to the very indistinct pre- 
liminary notices in which the results of the author’s developmental 
researches are presented. We give the characteristics of these three 
divisions as follows in the words of their author :— 

“i. Greg. Isoplaste.—The germs of the Gregarine and the series 
of the Myxomycetes appear at the same time, and both take their 
origin from the differentiated body-mass, but each for itself and in- 
dependently one of the other. Cystoplasta represents Myxomycete 
forms by plasmodia. 

“ii. Greg. Proteroplaste—The body-mass of the Gregarine, 
when generatively mature, becomes differentiated into a Myxomycete 
plasmodium. The Gregarine germs take their origin from this. 
Acystoplasta. 

“ii. Greg. Hysteroplaste.—The Gregarine germs first originate 
from the differentiated body-mass; the series of the Myxomycetes 
proceeds exclusively from certain transformations of the germs of 
the Gregarines (ameeboid bodies). Cystoplasta. Myxomycete forms 
represented by plasmodia with radiating processes, pigments, cal- 
careous corpuscles, and Mycetozoa.” 

The Myxomycete forms which produce psorospermiz are regarded 
by the author as derived from disintegrated Proteroplasta, but the 
“sickle-shaped bodies found in Vertebrata and claimed as Gregarines 
by Eimer,” on the other hand, as allied to the Hysteroplasta. 


Psorospermie in Man.*—B. Grassi has found in the excrements 
of a boy and of a young man during a long period (25 months in 
the first case) numerous bodies which after much hesitation he 
describes as oval Psorospermiz (Coccidia). They exhibit a number 
of variations in size and form; they are sometimes globular, some- 
times elliptical; in the first case they generally measure ‘008 mm. 
in diameter, but in the latter usually ‘008 to :006 mm.; they have a 
distinct, and in the larger individuals a double-contoured test, and 
finely granular contents, completely filling the shell and containing 

* Rendic. R. Istit. Lombard., iii. (1880) 3 pp. Cf. Zool. Jahresber, Neapel for 
1880, i. p. 162. 


358 SUMMARY OF CURRENT RESEARCHES RELATING TO 


from one to eight roundish nucleoid bodies. The contents may also be 
sometimes quite homogeneous or somewhat condensed and retracted 
from the test, and in many the protoplasm contained from one to six 
semilunar homogeneous glistening bodies, which, however, judging by 
the very poor figure given of them, show no special resemblance to 
the sickle-shaped bodies of Coccidia. The behaviour of these bodies 
towards various reagents and staining substances is also described. 
From all this the Coccidian character of these structures seems to be 
still doubtful. The two patients exhibited no complaints to which 
the presence in them of these parasites might be referred. 


Myxosporidia.*—Under this term, which is introduced | by Pro- 
fessor O. Biitschli, may be mentioned the so-called parasitic plasmatic 
tubes of the pike’s bladder, discovered by Lieberkiihn, and belong- 
ing to the so-called Fish-Psorospermiz, so widely distributed in 
these animals. According to Gabriel, they have no intimate con- 
nections with the Gregarine, as Leydig, and later Lieberkiihn, have 
endeavoured to show; the following are the chief reasons which he 
advances for thisopinion. These very variously shaped protoplasmic 
structures at no period of their life possess an envelope like that of 
Gregarine, and they are entirely non-nucleate. Moreover, the surface 
of the body frequently developes extensions and radiating processes 
of a very peculiar character, appearing now pointed, now finely 
fringed, sometimes hair-like and often branched as well, and consist- 
ing of protoplasm which is quite transparent, though not entirely 
without granules. These stellate processes cannot be directly com- 
pared to pseudopodia, for though they are protruded they are not 
retracted again. They consist “of what may be called a thread- 
drawing substance, which can issue forth with ease but cannot be 
again retracted.” A substance of this nature is said to be peculiar 
to the protoplasm of Myxomycetes and to certain plasmodia resembling 
Myxomycetes, and connected with the development of true Gre- 
garines. Real phenomena of motion have not however been observed 
by the author in these protoplasmic structures. A further argument 
against their Gregarine nature is the presence in them of a yellow 
pigment of various shades, pigment of which kind is frequently 
found in the Myxomycetes. 

To what was known of the formation of the spores of the 
true Psorospermiz which occur within the protoplasmic structures, 
Gabriel is hardly able to add anything. According to him, the spores 
are developed, as already stated by Leydig and Lieberkiihn, in spaces 
or vacuoles which are at first unprovided with walls, and later, but 
not in all cases, become converted into vesicles by formation of a 
wall. The spores are formed within these vacuoles in a manner 
which is compared by the author to a process of secretion. Inasmuch 
as several spores may develope within a single vacuole, Gabriel terms 
the vacuoles “ polysporogenetic centres of development,” and sees in 
them a veritable contrast to the “single, monosporogenetic forms of 

* Ber. naturw. Sect. Schles. Ges., 1879, pp. 26-33. Cf. Zool, Jahresber. 


Neapel for 1880, i. pp. 162-4. 
+ Op. cit., p. 162. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 359 


development” of the Gregarine germs (Pseudonavicelle). Of the 
structure of the spores we learn almost nothing ; in particular, the 
remarkable thread-cell-like structure of the so-called polar corpuscles 
appears to have quite escaped the author, and he takes no notice at 
all of Balbiani’s work on the Psorospermie of fish. He has not 
been able to observe any bursting of the spores and emission of an 
amceboid body. 

On the other hand, he has observed a method of development of 
the spores which is carried out inside the bladder, but which he 
gives with some reserve. It commences with the solution and absorp- 
tion of the containing capsule, but then proceeds in two different 
ways. Hither the central protoplasmic part of the spore fuses with 
the two polar corpuscles into a single protoplasmic mass, or the parts 
remain distinct. In the latter case the spore-contents are said to 
break up (in a manner which is not very intelligible) into two pieces, 
seldom more. Finally, spore-contents, which have become granular 
and vacuolated, are said to develope small, strongly granular plas- 
modia, which become the protoplasmic structures first described. The 
existence of another process of spore-development appears to the 
author to be certain, seeing that at some time or another infection 
must take place from outside. As already indicated, the author draws 
from his results the conclusion that the structures which we have been 
considering cannot be included with the Gregarine, but must be con- 
sidered as “spore-forming Myxomycetoid plasmodia,” not, however, 
exhibiting the entire characters of the group Myxomycetes. Hence 
they are to be regarded as a tribe whose systematic position lies 
between the Myxomycetes and Gregarines, a circumstance which 
appears to the author to have a most important bearing on the rela- 
tions which he represents to exist between these two groups. 

Morphology of Protozoa.—L. Maggi * again calls attention to the 
differentiation of a mesoplasm between the ecto- and endoplasm, a 
fact of deep importance in his view, and first discovered by him 
in certain Amcebe and the genus Podostoma. The demarcation of 
these three regions in the protoplasm of the body of certain Protozoa 
appears to him of especial interest for this reason, that they exhibit an 
analogy with the three blastodermic layers of the Metazoa. The 
ectoplasm gives rise to the pseudopodia, which effect the relations 
with the outer world; on the other hand, the mesoplasm supplies 
the contractile vacuole, an organ of circulation, excretion, and exhala- 
tion ; lastly, the entoplasm contains the “ entoplasmatic organs,” viz. 
the digestive cavity, the nucleus, and nucleolus, the two last being 
the organs of reproduction. Thus it is the mesoplasm and entoplasm 
which support the vegetative functions of life. Grimm also f has 
pronounced in favour of the view of the differentiation of a mesoplasm 
and drawn the same parallel with the germinal layers of the Metazoa. 

G. Cattaneo ¢ expresses opinions with regard to the morphological 

* Bollet. Scientif., i. (1880) pp. 81-3. Cf. Zool. Jahresber. Neapel for 1880, i. 
R: Ae sc Obaibeibutioas to the Knowledge of the Simplest Animals,’ 1877, in Russian. 

} Atti Soc. Ital. Sci. Nat., xxii. (1880) p. 68 (2 pls.). Cf. Zool. Jahresber, 
Neapel, tom. cit., p. 123. 


360 SUMMARY OF CURRENT RESEARCHES RELATING TO 


structure of plastids precisely similar to those propounded in 1879 
by Maggi. In his view the protoplasm and plasson are made up of 
numerous simple albuminoid particles, which he agrees with Maggi 
in naming plastidules and which represent the simplest morphological 
elements. The simplest forms of these plastidules, the so-called pro- 
toplastidules, are said to be the granules devoid of independent motion 
which are found in organic infusions; with these may perhaps be 
ranked as structures of similar morphological value, the free solitary 
spherical Bacteria, the Cocci, and Micrococci. If these protoplasti- 
dules become differentiated in such a way as to form around them- 
selves parts of unequal physiological values, there arise the autoplasti- 
dules, among which must be included the simple Microbacteria, such 
as Bacterium termo, the Monococci and Monobacteria of Billroth, the 
Desmobacteria (Bacillus), and the Spirobacteria (Spirillum). By 
colonial growth, on the other hand, the protoplastidules give rise to 
symplastidules, among which are placed the social forms of the 
Bacteria, as the Diplobacteria, the Strepto-, Glio-, and Petalobacteria, 
and also the Amphiasters (Kernspindeln), and stellate figures of cells 
in process of division. A combination of plastidules which are not 
all developed in the same way forms a plastid. 

Differentiation generally takes place in a radiating manner, so 
that an outer and an inner mass are formed, differing somewhat from 
each other. The simpler forms are in this case the protoplastids, 
which include the non-nucleate gymno- and lepo-cytodes, and the 
simpler nucleate gymno- and lepo-cellule. By further differentiation 
these protoplastids result in autoplastids. The author considers 
that the different layers of differentiated substance in a highly 
developed autoplastid, viz. ecto-, meso-, entoplasm, nucleus, and 
nucleolus, may be compared to so many cytodes concentrically 
grouped; and thus an autoplastid of this kind is to be regarded 
anatomically (though not genetically) as a colony of cytodes. 

The colonies of plastids are described as symplastids. The author 
includes among them the Gregarine. 


Eozoon Canadense.*—Professors King and Rowney deal with the 
question of the organic nature of Hozoon and of simulation of organ- 
ized structures generally, their opinion being decidedly in favour of 
its mineral origin. 

In the first place they state that the “typical nummuline wall” 
is a pectinated form of chrysolite, due to modification of that 
allomorph of serpentine, where the fibres of the mineral ultimately 
become separated acicule with calcareous interpolations. The 
“canal system, &c.,” is rather more obscure in its origin. It is 
frequently due to the peculiarities of a layer of flocculite (a non- 
fibrous allomorph of serpentine), which on undergoing some solvent 
or decreting process, is apt to be shaped into irregular configurations. 
So likewise the “chamber castes” of the acervuline variety are 
identical with the variously lobulated crystalloids characteristic of 

* King and Rowney, ‘ An Old Chapter in the Geological Record with a New 


Interpretation ; or, Rock Metamorphism and its Resultant Imitation of Organ- 
isms.’ 8vo, Van Voorst, 1881. See Geol. Mag., ix. (1882) pp. 231-6. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 361 


Tyree “marble” and similar rocks, due, as the authors believe, to 
decretion of the original silicate. As regards the calcitic layer con- 
taining the “intermediate skeleton” in typical specimens of Eozoon, 
the calcite composing this part is “plainly a replacement pseudo- 
morph after serpentine.” This explanation would account for the 
alleged cases of “chambers” and “canal system” preserved in 
calcite. 


BOTANY. 


A. GENERAL, including Embryology and Histology of the 
Phanerogamia, 


Chemical Difference between Dead and Living Protoplasm.— 
In the paper by Dr. O. Loew and T. Bokorny, noticed under the 
above heading at vol. 1. (1881), pp. 906-7, it should have been stated 
in the description of the method employed for producing the reduction 
of silver by the protoplasm, that the silver nitrate solution must be 
used in an alkaline condition, produced by the addition of ammonia. 
Similarly, to obtain reactions with gold chloride and platinum 
chloride respectively, the previous addition of caustic soda to the 
solution of the salt is necessary. 

Dr. Loew describes the preparation of the silver solution as 
follows:—(a) Prepare a 1 per cent. solution of nitrate of silver; 
(b) mix 18 cc. of a solution of potash (1°33 sp. gr.) with 10 ce. of 
caustic ammonia (1°96 sp. gr.), and dilute with water to 100 ce. 
Mix 1 ce. of each of (a) and (6) and dilute the 2 cc. to 1 litre imme- 
diately before use. 


Occurrence of Aldehydes in Chlorophyllaceous Plants.*—J. 
Reinke and Kratschmar assert the presence of volatile reducing 
substances in all the chlorophyllaceous groups of plants; in alga, 
lichens, mosses, ferns, conifers, and angiosperms; while they are 
absent from fungi and etiolated seedlings of flowering plants. Their 
occurrence appears therefore to be connected with the presence of 
chlorophyll, though they may spread to the parts which do not 
contain this substance. The authors determined the presence of two 
such substances of different reducing powers. From the powerful 
reducing properties, it is inferred that these substances belong to 
the class of aldehydes; and their power of reducing a neutral 
silver solution in the cold appears to identify them with formic 
aldehyde. If this should not be confirmed, they may possibly be 
identical with acetol or with some other “ ceton-alcohol.” 


Organ not hitherto described in the Vegetable Embryo.j— 
G. Briosi describes a part of the embryo which he finds in some 
plants, and which has hitherto escaped attention. Ifthe exalbuminous 


* Berichte deutsch. chem Ges., xiv. (1881) p. 2144. See Bot. Ztg., xl. (1882) 
p. 57. 
: + G. Briosi, Sopra un organo finora non avvertito di aleuni embrioni vegetali. 
15 pp. (8 pls.) Rome, 1882. 
Ser. 2.—Vou. II. 2B 


362 SUMMARY OF CURRENT RESEARCHES RELATING TO 


seed of Eucalyptus globulus is carefully examined, the embryo is seen 
to consist of two cotyledons and a radicle without plumule; but the 
radicle is found not to be of very simple structure. It is not perfectly 
cylindrical, but its lower extremity is somewhat club-shaped. A 
longitudinal section shows that its central portion is composed mainly 
of the tigellum or hypocotyl, surrounded near its lower extremity by 
a kind of collar through which the radicle projects. This collar is 
composed entirely of parenchymatous tissue containing no fibro-vascular 
bundle, and is completely covered with white hairs. As the seed 
germinates it developes to a considerable size, but finally disappears, 
leaving not a trace behind. The author believes that it is endowed 
with a nutritive function. He has observed it in the embryo of 
several genera of Myrtacez, also in Onagrariez: and Lythrariez. 


Studies of Protoplasm.*—In a series of papers under this title, 
J. Reinke proposes to classify the substances out of which proto- 
plasm is composed under the three heads of “constant,” “ variable,” 
and “ accessory.” 

The author regards the first product of the assimilation of carbonic 
acid as probably formic aldehyde, according to the equation CO,;H, — 
20 = COH,. From this various polymeric substances are then pro- 
duced, as, for example, grape-sugar, 6 CH,O0 = C,H,.0,. The author 
distilled leaves of the poplar, willow, and vine with water, and reduced 
the distillate by Fehling’s solution and solution of silver nitrate, by 
which the presence of an aldehyde-like substance was determined. 
The same result was obtained from roots of the willow, and with 
leaves which had remained for eight days in the dark. 


Composition of the Protoplasm of Athalium septicum.j—In 
continuation of previous inyestigations,t J. Reinke and H. Rodewald 
give fresh analyses of the protoplasm of Athaliwm septicum. The 
plasmodium has, when fresh, an alkaline reaction. A turbid yellowish 
fluid, the enchylema, can be obtained by pressure ; it contains albu- 
minoids, and can be coagulated at a temperature of 58-64°C. The 
fresh plasmodium contains 71°6 per cent. of water ; the following is 
an analysis of the ash :— 


Per cent. 
Carbonictacid yi... was ase ee ole ee OO LO 
Phosphoriciacia’..2” #5." Vi Foe ee 649 
Sulphuric acid 5 i.) 05 Wel sie cate ce ORAS 
Chiorine st 2st tee ine toe ee te oe asenOeen 
Sesquioxidejof iron. das i ich as.) Gin ae AO 
Tinie fee Ley dc. Viegas epee Tees ce Oe 
Oxide ofmarnesium=, (% 2 es) acer a OSM 
Potassa Behe ace HANS eats) Uae hbase! mera la tb De: 
Sodadicrs ey i: dae Mes eS ee) bo ree 

99°92 


Extraction of the air-dried substance by ether yields from 5-36 
to 8:13 per cent. of extract, which saponifies in alcoholic solution, and 
* Unters. aus dem bot. Lab. Gottingen, 1881, pp. 74-184, 187-202. 


+ Ibid., pp. 1-75. See Bot. Centralbl., viii. (1881) p. 292. 
‘t See this Journal, i, (1881) pp. 283, 918. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 363 


yields about 21 per cent. of paracholesterin. The volatile fatty acids 
found were propionic, butyric, caprionic, and probably caprinic acid, 
the non-volatile fatty acids, stearic, palmitic, and oleic acids. 

The spores contain a larger quantity of asparagin than the proto- 
plasm. The presence of acetic and oxalic acids was certainly, that of 
lactic acid probably, determined. In perfectly fresh protoplasm, 
Hoppe-Seyler’s method determined the presence of myosin and 
vitellin; in the glycerin-extract was a ferment (pepsin) with the 
property of dissolving albumen. 


Properties of the Protoplasm in Urtica urens.*—F. Kallen 
has investigated the phenomena displayed by the protoplasm of the 
stinging-nettle, in the merismatic cells, the medullary cells, the 
epidermal cells, the hairs, the glandular hairs, the stinging hairs, the 
cortical parenchymatous cells, the bast-fibres, the cells of the soft 
bast, the cambium cells, the wood-vessels, and the prosenchymatous 
cells. The following are the general results arrived at. 

In all the cells the nucleus is densest and largest in comparison 
to the size of the cell in the youngest stage. In older stages of the 
parenchymatous cells there is frequent fragmentation ; this occurs in 
the pith, the cortex, and the unthickened wood-parenchyma-cells. 
The finely punctated protoplasm exhibits at all stages a coarsely reti- 
culate structure, as in the medullary cells; but the interstices are 
covered by a hyaline layer of protoplasm, so that the protoplasmic 
utricle is nowhere interrupted. The nucleus does not usually dis- 
appear before the protoplasm ; in the sieve-tubes only does this take 
place; while in older stages of the bast-fibres, the nucleus is partially 
absorbed. In the xylem-vessels the nucleus and protoplasm never 
disappear. Crystalloids were in a few cases found in the nuclei of 
the hairs. The multinucleated bast-fibres contain latex. The nuclei 
of the bast-fibres multiply by fragmentation, not, as Treub supposes, 
by division. 

Fertilization of Salvia splendens.t—W. Trelease describes the 
“ ornithophilous” structure of this Brazilian species, the structure being 
especially adapted for fertilization by humming-birds. It is proter- 
androus, and there is no arrangement to facilitate fertilization by 
either day or night-flying insects. 


Reproductive Organs of Loranthacee.{—M. Treub has investi- 
gated the development and structure of the sexual organs in this 
natural order in the case of Loranthus spherocarpus. The rudimentary 
carpels enclose a small cavity, in the middle of which rises a hemi- 
spherical central papilla, an elongation of the axis. This papilla is 
so connected with the carpels that only three or four canals remain 
open, and these also soon disappear. Before this complete union is 
effected, there can be detected in each free lobe of the central papilla 
hypodermal cells of larger size, which soon assume a nearly vertical 

+ Flora, Ixv. (1882) pp. 65-80, 81-92, 97-105 (1 pl.). 

+ Amer. Natural., xv. (1881) pp. 265-9. 

{ Ann. Jard. bot. Buitenzorg (Java), ii. (1881) pp. 54-76 (8 pls.). See Bot, 
Ztg., xl. 1882) p. 59. ; 9 

4B 


364 SUMMARY OF CURRENT RESEARCHES RELATING TO 


position, and divide, by transverse septa, into three superposed cells. 
Of the four or five rows of cells thus formed, the uppermost daughter- 
cell of one only developes, and becomes the embryo-sac; all the rest 
are resorbed, including the two belonging to the same row. Since 
each of the originally free lobes from the central papilla forms an 
embryo-sac, and the number of these lobes corresponds to that of the 
carpels, the number of embryo-sacs in the ovary also corresponds to 
that of the carpels. Round the embryo-sac is formed, partly out of 
the previous epidermal cells of the central papilla, a sheath of amy- 
laceous cells, which is prolonged upwards into a similar row, while 
in the lower part of the ovary is developed a sheath of collen- 
chymatous tissue open above. ‘lhe embryo-sacs elongate to an extra- 
ordinary extent both upwards and downwards, following upwards the 
row of amylaceous cells till they reach the base of the style, and there 
somewhat expand; while they extend downwards to the base of the 
collenchymatous sheath. Their nucleus now divides; one of the 
daughter-nuclei moves into the upper expanded portion of the sac 
and again divides. 

The first wall in the fertilized germinal cell is longitudinal, 
followed in each half by several transverse septa. The lower cells 
of this suspensor divide further, while the upper ones grow to an 
extraordinary length, and force the lower apex of the embryo between 
the first endosperm-cells, which have at the same time been formed 
in the lower part of the embryo-sac; the embryo being thus finally 
attached to the end of the double thread which constitutes the sus- 
pensor, and which is rolled up between the embryo and the endo- 
sperm. 'The endosperm cells now increase rapidly in number in its 
lower and peripheral parts, thus crushing the suspensor, which finally 
entirely disappears. The radicular end of the embryo then penetrates 
into the endosperm and consumes it; and the embryo becomes com- 
pletely enclosed in the collenchymatous sheath; rising up into it, 
partly in consequence of the pressure of the lower part of the endo- 
sperm. 

The central papilla formed in the centre of the ovarian cavity was 
regarded by Griffith as a placenta with rudimentary ovules; by Hof- 
meister as an orthotropous nucleus without integuments, in which 
several embryo-sacs are formed, and the chalaza of which is repre- 
sented by the collenchymatous sheath. Treub supports the former 
view, and considers the axial portion of the papilla to be of the 
nature of a placenta, its three or four lobes being rudimentary 
ovules; a view confirmed by the somewhat similar structure presented 
by the Santalacee. Griffith thought that the single embryo was the 
result of the coalescence of several ; Treub is unable to confirm this ; 
but, on the other hand, found frequent evidence of the abortion of 
embryos, one only of which reaches maturity. 


Structure and Mode of Formation of Spermatozoids,*— 
K. Zacharias has investigated the behaviour with different reagents of 
the various constituents of spermatozoids, chiefly those of Nitella 


* Bot. Ztg., xxxix. (1881) pp. 827-38, 846-52. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 365 


syncarpa and Chara aspera. The spermatozoid he regards as com- 
posed of three parts—the spiral band, the paler terminal portion or 
vesicle, and the cilia. 

A solution of pepsin does not dissolve the spiral band ; it becomes, 
on the contrary, more distinct and strongly refractive, either retaining 
altogether its original form, or becoming more or less short and 
thick; the separate coils sometimes coalesce into a single homoge- 
neous refractive lump. The cilia are almost completely dissolved, 
while the posterior vesicle swells up, and finally again contracts, <A 
dilute solution of sodium chloride causes the spiral band to swell up 
slowly, a peripheral denser part becoming differentiated from a central 
less dense part; the latter finally dissolves entirely, the former only 
being left in the form of a fine pellicle, which contracts and is coloured 
brown by a solution of iodine in potassium iodide. The posterior 
vesicle swells up, and then again contracts. The cilia do not 
contract, and are affected only by concentrated hydrochloric acid. 
The reactions with pepsin are also described in detail. 

The spermatozoids of Muscinee (Fegatella and Lunularia) agree in 
their behaviour, in all important points, with those of the Characee. 
Those of ferns and of Marsilea differ in some particulars. The spiral 
bands of the spermatozoids of an Australian Marsilea were distin- 
guished by their extraordinary resistance to solvents, as was also the 
case with those of some ferns (Hemitelia capensis); while the cilia 
agreed in their properties with those of the Characez. 

The author then compares the properties and reactions of the 
Spermatozoids of cryptogams with those of the spermatozoids of 
animals, as investigated by Miescher, Schweiger-Seidel, Flemming, 
and others, and finds that in many respects the properties of the cilia 
and spiral bands of cryptogams agree respectively with those of the 
tail and head of animal spermatozoids. A similar relationship is 
found in the development of the different parts in spermatozoids 
- belonging to the two kingdoms. 

As regards the history of development of the spermatozoids of 
Chara and Nitella, the nuclei of the young mother-cells are composed 
of parts of various refrangibility, and each nucleus contains a 
nucleolus. The peripheral layer of the nucleus subsequently becomes 
denser, and the central part less dense. The nuclei at this time 
approach the outer wall of the cell, the rest of the protoplasm col- 
lecting at the opposite side. From the peripheral layer is formed the 
spiral band of the spermatozoid. The author was unable to decide 
whether the nucleolus takes any part in the formation of the sperma- 
tozoid, or whether the cilia are formed out of the nucleus, or, as 
Schmitz states, out of the cell-protoplasm. 

The author considers that both the course of development and 
the chemical reactions indicate that in all probability the head 
of animal and the spiral band of vegetable spermatozoids owe the 
nuclei which they contain to the fact that they are formed from the 
nucleus of the mother-cell; while, on the other hand, the tail of 
animal and the cilia of vegetable spermatozoids are formed out of the 
cell-protoplasm. 


366 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Cell-nucleus in the Mother-cells of the Pollen of Liliacez.*— 
Investigations on this point have been carried out by A. Lalewski, 
mostly on Liliwm candidum and Allium Moly. His mode of preparation 
was to place transverse sections of the young stamens in a 1 per cent. 
solution of acetic acid, slightly coloured by methyl-green. After a 
time, the nucleus acquires a beautiful blue colour, while the remaining 
contents of the cell continue nearly or quite colourless. 

The large and fully developed cell-nucleus of Lilium candidum is 
enclosed, not in a pellicle of denser nuclear substance, but in an 
extremely delicate coat of cellulose. Immediately beneath the surface 
it usually contains a finely granular semi-transparent nucleolus, which 
is not coloured by methyl-green, and which remains unchanged up to 
a certain period in the division of the nucleus, After the initial 
stages, the membrane of the nucleus is resorbed, the vermiform 
structures which had been formed become straight, and place them- 
selves in the equatorial region in the longitudinal axis of the cell, and, 
after completely coalescing at the poles, constitute the well-known 
“nuclear spindle.” According to the author, the vermiform con- 
stituents of the nucleus are also enclosed in an exceedingly delicate 
coat or sac of cellulose, filled with dense protoplasm, which draws 
towards the equator, while the empty ends of the sacs become 
elongated, finally meeting and coalescing at the poles of the nucleus. 
Hence the number of nuclear or spindle-threads is normally the same 
as that of the elements of the nuclear plate. When the number of 
threads is larger than that of the elements of the nuclear plate, this 
is due to the protoplasm of some of the smaller elements of the plate 
being entirely used up in the formation of spindles. This stage is 
shortly followed by the splitting of the nuclear plate, which usually 
takes place by the protoplasm of the elements of the plate beginning 
to move in opposite directions towards the two poles, and thus 
assuming an elongated form. Reaching the wall of the cell, these 
strings of protoplasm coalesce in pairs into a V-shaped structure. 
The nucleoli, which have up to this point remained unchanged, now 
take part in the further changes in the cell. They move towards the 
middle of the cell, break up into smaller portions, and form in this 
manner both the protoplasm of the cell, which is compressed from all 
sides at the plate, and the material for forming the cell-plate. At 
the line of contact of the plate with the cell-wall of the mother-cell, 
the young cell-wall first appears in the form of a ring, which quickly 
grows inwards, and finally developes into a perfectly continuous 
division-wall. Inthe daughter-cells thus formed the nuclei divide in 
just the same way as in the mother-cell. 


Crystalloids in the Cell-nuclei of Pinguicula and Utricularia.j— 
According to further observations of J. Klein, the crystalloids found 
in the cell-nucleus of these two plants strongly resemble not only one 
another, but also those found in Lathrea squamaria, a point of 
interest from the fact that Eichler advocates a closer genetic relation- 

* Kosmos, 1881, pp. 158-74 (1 pl.). See Bot. Centralbl., viii (1881) p. 375. 


} Pringsheim’s Jahrb. fiir wiss. Bot., xiii. (1881) pp. 60-73 (1 pl.). Cf. this 
Journal, i. (1881) p. 477. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 367 


ship between this species and the two former than has generally been 
supposed. This resemblance relates not only to their form, but also 
to their chemical properties. They differ from ordinary proteinaceous 
erystalloids in being more soluble in water and in the cell-sap of 
dead cells. Utricularia vulgaris contains also crystals of calcium 
oxalate of regular octahedral form, but occasionally of a peculiar 
stellate or rod-like shape. 


Cystoliths in Momordica.*—The oceurrence of cystoliths has 
been at present determined only in the Urticacee and allied orders 
and in the Acanthacee and Cucurbitacee. Dr. O. Penzig now finds 
them in several species of Momordica (Cucurbitacex), especially M. 
Charantia and echinata. They occur almost exclusively in the leaves ; 
in some instances also in the bracts. Their location is entirely in the 
lower layers of the epidermis (hypophyll) ; they are always attached 
to the radial lateral walls of the cell, presenting in this point a con- 
trast to those of Ficus. They are never solitary, but always two or 
more in a corresponding number of adjoining cells. 

In Momordica echinata the cystoliths are almost always in pairs, 
and they spring in adjoining cells from opposite points of the same 
wall. In the earliest stages of the leaf the cells of the hypophyll are 
all precisely alike. The mother-cells of the cystoliths then become 
distinguished by their larger size and more strongly refractive cell- 
contents. When they have attained about four times the size of the 
ordinary cells, they divide by an anticlinal division-wall, and the two 
cells thus formed may divide further or not. Ata later period the 
mother-cells of the cystoliths are entirely destitute of chlorophyll 
and starch, containing only abundant protoplasm. A small protuber- 
ance of cellulose then appears on each side of the partition-wall, 
which developes into a cylindrical or club shape; and it is only when 
nearly fully developed that the deposition of calcium carbonate takes 
place in it. The mature cystolith always has, as in the Urticacezx, 
somewhat the appearance of a bunch of grapes. 

In M. Charantia usually three, four, or five contiguous cells 
produce cystoliths, one in each, and they then spring all from a 
common central angle; but eventually their base widens out, so as 
almost entirely to fill up the cells. The same process then infects 
a number of adjoining cells, so that eventually a large and complicated 
mass is formed, occupying a large number of the cells of the epidermis. 

When the lime is removed by weak acetic acid, a slight skeleton 
remains, which is coloured dark yellow, passing into brown, by iodine 
solution or chlor-iodide of zinc. The‘cellulose reaction can, however, 
be obtained from it with care, and it probably consists of impure 
cellulose. 


Sphero-crystals.;—J. Schaarschmidt has detected organic sphero- 
crystals in four natural orders of flowering plants in which they haye 
not previously been observed, viz. Euphorbiacew (Huphorbia), Rutaceze 


* Bot. Centralbl., viii. (1881) pp. 393-400 (3 pls.). 
+ Magyar Novénytani Lapok, v. (1881) pp. 134-8. See Bot. Centralbl., ix. 
(1882) p. 46. 


368 SUMMARY OF CURRENT RESEARCHES RELATING TO 


(Haplophyllum), Urticaceze (Urtica), and Palme (Nunnezharia and 
Pheniz). 

In Puphorbia Tirucalli they are unusually beautifully developed. 
Tn an early stage a centre of formation may be observed, which may 
be a chlorophyll- or starch-grain; round this is formed a massive 
nucleus, to which the crystals are attached with a radiate arrangement. 
Subsequently they exhibit evident stratification. The radiate portion 
is at first colourless, afterwards yellowish brown; the whole is 
evidently crystalline. The sphero-crystals are usually readily 
soluble in cold water; their behaviour towards reagents is similar to 
that of inulin. 

In Urtica major the sphero-crystals are found in the guard-cells of 
the stomata and neighbouring cells, less often in the fundamental 
tissue. They are dark brown, insoluble in cold or in boiling water, 
and appear allied in their nature to hesperidin. 

In Nunnezharia they occur in the peripheral fundamental tissue 
of the stem, forming large yellow clusters, also in the leaves, bracts, 
and rachis of the inflorescence. They are slowly soluble in cold 
water, and exhibit the closest resemblance to inulin. 


Structure of Starch-grains.*—A. Meyer discusses Nigeli’s theory 
of the formation of starch-grains by intussusception, and A. F. W. 
Schimper’s{ that they are sphero-crystalloids of a carbohydrate formed 
by apposition of concentric layers ; and argues in favour of the latter, 
from the similarity of the phenomena they present to those of arti- 
ficially prepared sphero-crystals of a carbohydrate such as sugar. 
In these the three following characters are found, which agree with 
those of starch-grains :—(1) Variations in the external conditions 
which affect crystallization cause also the formation of layers; (2) the 
centre of crystallization is less dense than the surrounding layers ; 
(3) the youngest external layer is the densest, the density of the suc- 
cessive layers towards the interior decreasing with their age. 

A full description follows of the starch and starch-generators in 
the rhizome of Iris pallida and germanica, the following being the 
general conclusions arrived at:—(1) The starch-generators in the 
rhizome of Iris only perish with the death of the cells in which they 
are found; (2) in them not only the formation but the solution of 
starch- -grains takes place; (3) both internal and external solution of 
the starch-grains takes place in the cells; (4) the only simple 
explanation of all the phenomena observed is presented by the hypo- 
thesis that the starch-grains increase in substance by apposition. 


Assimilating Tissue.{|—G. Haberlandt supports the view of 
Schwendener that the structure and arrangement of the cells which 
constitute the assimilating tissue are dependent on the process of 
assimilation, ‘The more important cell-forms of which it is composed 
may be classified as follows :— 


* Bot. Ztg., xxxix. (1881) pp. 841-6, 857-64 (1 pl.). 

+ Seo this Journal, i. (1881) pp. 481, 909. 

a Pringsheim’s Jahrb. fiir wiss. Bot., xiii, (1881) pp. 74-188 (6 pls.). Cf. this 
Journal, i, (1881) p. 912. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 369 


1, Elongated cells of tubular and cylindrical, rarely prismatic 
shape. ‘Their position in relation to the surface of the assimilatine 
- organ varies. Most commonly they are vertical, in which case they 
are termed palisade-cells, less often parallel to the surface. When 
provided with arms or protuberances, they may be called branched 
palisade-cells; funnel-cells, when the end nearest the surface is of 
larger diameter than the other end. 

_ 2. Tabular polyhedral cells, with or without infoldings of the wall. 

3. Isodiametric cells, with a tendency to rounding. 

4, Spongy parenchymatous-cells, of stellate form and much 
branched. 

The cell-walls are sometimes furnished with simple pits, and are 
usually thin and delicate. The chlorophyll-graing are as a rule 
from two to six times more numerous in the palisade-tissue than in 
the spongy parenchyma, from which the writer infers that the formcr 
is in an especial manner tle assimilating tissue of plants. The 
assimilating cells frequently show infoldings of the cell-walls, as in 
Pinus, the object being to increase the surface of cell-wall, and thus 
provide room for a larger number of chlorophyll-grains. These 
folds are so arranged as to facilitate to the greatest possible extent the 
abduction of the products of assimilation. 

Dependent on the characters already mentioned, the author 
classifies the various forms of assimilating tissue under ten types, 
arranged under the following heads:—(1) The assimilating tissue 
serves also as an abducting tissue. (2) Both these kinds of tissue are 
present, the products of assimilation passing out of the former into 
the latter. (3) Besides these two kinds there is also a special con- 
ducting tissue, through which the products pass in their way from 
the assimilating to the abducting tissue. 

The spongy parenchyma subserves three distinct physiological 
functions :—(1) It is peculiarly the transpiring tissue of the leaf. 
(2) It is the conducting tissue. (8) In consequence of the larger or 
smaller quantity of chlorophyll which it contains, it is an assimilating 
tissue. 

Light, which is the most important external factor in assimilation, 
while exercising a powerful influence on the arrangement of the 
assimilating system, scarcely affects its anatomical structure. It 
occasions the peripheral position of the special assimilating cells, 
and, in dorsiventral organs, their production on the illuminated side. 
The frequent occurrence of palisade-tissue is explained by the fact 
that the position of elongated cells at right angles to the surface of 
the organ favours the complete and intense illumination of the 
organ. 

Bio assimilating cell adjoins, at some part of its walls, the 
aerating system or intercellular spaces, which also serve to prevent the 
passing of the products of assimilation in unadvantageous directions. 

The firmness of the assimilating tissue is secured by a variety of 
contrivances; as the thickening of the walls of the palisade-tissue in 
some species of Cycas, the columnar cells in Hakea, and the frequent 
occurrence of branched sclerenchymatous cells among the green cells. 


370 SUMMARY OF CURRENT RESEARCHES RELATING TO 


There are often found cells and tissues which serve purposes of 
lecal assimilation, as glandular and stinging hairs, the guard-cells of 
stomata, &e. 

The origin of the assimilating tissue varies greatly. It may 
arise from the cambium, the fundamental parenchyma, or the young 
epidermis. 

The fundamental parenchyma of the stem passes without inter- 
ruption into the parenchyma of the leaf-stalk, which is itself in con- 
nection with the parenchymatous sheaths of the vascular bundles of 
the leaf; this entire system forming the principal channel for the 
passage of the products of assimilation. 

In addition to its primary function, the assimilating system of 
many evergreen leaves, as those of conifers, fulfils a secondary func- 
tion, viz. the storing up of the products of assimilation during the 
period of repose. 


Fibrovascular Bundles of Monocotyledons.*—The fibrovascular 
bundles of Monocotyledons are normally of two kinds, collateral, in 
which the xylem and phloém run side by side, and concentric, in 
which a ring of xylem, usually closed on all sides, encloses a central 
mass of phloém. lL. Kny points out that not a few monocotyledons 
possess fibrovascular bundles which do not correspond to either of 
these types. Not unfrequently two or more groups of soft bast are 
separated by masses of sclerenchyma. In a number of palms bipar- 
tition of the phloém occurs, and in Rhapis flabelliformis tripartition is 
the rule. Sclerenchyma frequently forces its way from both sides 
between the phloém and xylem, separating them from one another. In 
Testudinaria and other Dioscoreacee the separation of the phloém 
into two distinct groups is especially marked. The object both of 
this separation and of the interposition of sclerenchyma, the author 
believes to be the mechanical strength gained thereby. 


Sieve-Tubes.{—E. Janczewski continues his researches { on the 
sieve-tubes of Dicotyledons, with especial reference to Aristolochia 
Sipho, Tilia parvifolia, and Vitis vinifera. 

They may be formed out of cambium-cells in two different ways: 
—(1) The cambium-cell, after detaching derivative cells on each 
side, developes the sieve-tube-cell directly; and the sieve-tubes are 
then arranged in radial rows, in contact with one another by their 
tangential walls; or (2) the cambium-cell divides longitudinally and 
tangentially into two cells of unequal size, of which the outer and 
larger one becomes the sieve-tube-cell either immediately or after 
the separation of lateral derivative cells, while the inner and smaller 
cell breaks up, by transverse division, into a row of parenchymatous 
cells. In this latter case they are separated from one another, and can 
touch one another only by their radial walls. A single cambium-cell 


* Verhandl. bot. Ver. Prov. Brandenburg, xxii. (1881) pp. 94-109. See Bot. 
Centralbl., ix. (1882) p. 79. 

+ SB, Akad. Wiss. Krakau, ix. (1881) (5 pls.). See Bot. Centralbl., ix. (1882) 
p. 15. 

{ Sce this Journal, iii. (1880) p. 824. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 371 


will sometimes produce from two to four sieve-tube-cells by transverse 
division, and production of sieve-plates on the transverse walls. 

The formation of sieve-plates commences with the development of 
symmetrical callus-warts on both sides of the terminal surfaces of the 
cell; the portions of cell-wall between these retain permanently their 
original chemical constitution, and form the future cellulose-sieve of 
the sieve-plate. A little later the callus-warts coalesce into a uniform 
mass covering the cellulose-sieve, in which perforations appear in 
place of the previous warts, causing a direct communication between 
the contents of adjoining sieve-tube-cells, 

The period of existence of the sieve-tube may be divided, in 
relation to its physiological function, into three epochs. The first is 
the active period, characterized by the open sieve-plates covered with 
callus, the parietal layer of protoplasm in the tubes, and the formation 
within them of mucilage and sometimes also of starch-grains. In the 
second or transition period the tubes lose their contents, and the 
sieve-plate is covered by a homogeneous mass of callus, which soon 
begins to become absorbed. The third or passive period relates to 
those sieve-tubes the plates of which are again opened, but consist 
simply of a cellulose-sieve without any deposit of callus; the contents 
have either entirely disappeared, or are often reduced to a small 
quantity of mucilage, and the sieve-tubes can then at most only serve 
for the transport of watery fluids. The relative length of these 
different periods varies greatly in different plants. 

The author finally examines the structure of the sieve-tubes of 
Monocotyledons, especially Typha latifolia and Phragmites communis. 
In the rhizomes of Phragmites the young sieve-tubes are developed 
out of the procambial cells, which first divide by tangential walls into 
two cells of unequal size ; the outer and larger of these developes 
immediately into the sieve-tube-cell, while the inner and smaller one 
divides, by a number of transverse and radial divisions, into cambi- 
form. The young sieve-tube is at first distinguished from the neigh- 
bouring procambial and young cambiform cells only by its larger 
dimensions, and by having lost its power of division. But soon the 
lateral walls thicken, and dots appear in them, and at the same time 
wart-like prominences on the terminal wall, which are at first small 
and are composed of pure cellulose, but gradually increase in size and 
assume a callose character. The subsequent processes resemble 
those in Dicotyledons. 

A great difference is observable between the behaviour of the 
sieve-tubes in Monocotyledons and Dicotyledons. In the latter, 
after having once become passive, they are constantly replaced by the 
activity of the cambium, and therefore endure only for a few months, 
or at most a few years; in the former, in consequence of the absence 
of cambium, the activity of the tubes lasts much longer, in fact, as a 
rule, as long as the organ itself in which they are found. 

The author concludes with the following general remarks. The 
elements of the sieve-tubes are always and everywhere prismatic, and 
are either horizontal or sharply truncate at the extremities. Their 
walls are always composed of pure cellulose, and are never strongly 


372 SUMMARY OF CURRENT RESEARCHES RELATING TO 


thickened. They are never entirely homogeneous, but are furnished 
with a larger or smaller number of dots, which in some cases always 
remain closed, as in Vascular Cryptogams, in others are at an early 
period covered with callose substance, being shortly afterwards 
changed into a true sieve by the appearance of numerous perforations, 
as in Phanerogams. The mature sieve-tube never contains a nucleus, 
having only a thin parietal layer of protoplasm which marks its 
vitality, and which entirely disappears with the death of the organ on 
the cessation of the life of the sieve-tube. 


Structure and Functions of Stomata.*—A. Tschirch distinguishes 
the following distinct parts of the stomatal apparatus :—(1) The 
eisodial opening, or opening into the anterior chamber; (2) The 
opisthodial opening, or opening into the posterior chamber ; (3) The 
central fissure; the true fissure between the two openings, which 
separates the guard-cells; (4) The outer and inner cuticular ridges, 
which are often circular and surround the two openings; (5) The 
outer stoma, or outer space which causes the depression in depressed 
stomata; (6) The circular wall, or margin which projects above the 
epidermis when the depression is pitcher-shaped ; (7) The circular 
ridges when the stoma is funnel-shaped; and (8) The epidermal 
opening, or actual orifice of the outer stoma. 

The author classifies the different forms of stomatal apparatus 
under eighteen types, which are described in detail. 

Excessive evaporaticn is prevented, firstly by the form of the 
stomata themselves; and secondly, by various special contrivances for 
the purpose, as the structure of the epidermis and accumulation in it 
of incrustation of calcium oxalate; coatings of wax on the epidermis; 
hairy formations; limitation of the large intercellular spaces in the 
merenchyma of the leaf; the nature of the cell-sap; and the form 
and (frequently vertical) position of the leaves. 

The number of stomata on a unit of surface in nearly related 
plants is larger in those which grow in moist, smaller in those 
which grow in dry habitats. The arrangement of the stomata is 
associated with purposes of protection. In those leaves which roll 
up when dry, the stomata on the concave side are enclosed; and the 
same is the case in grasses which grow in dry situations. 


Stomata of Stapelia.t—J. Jakd describes the structure of the 
complicated stomata of Stapelia variegata and trifida, which presents 
cousiderable analogy to that in many Monocotyledons, especially 
Tradescantia and Commelyna. 


Influences of External Forces on the Direction of Growth. 
—Sachs attributes the direction taken by pollen-tubes, after the 
grains attach themselves to the stigmatic papille, down the style, to 
the arrest of growth on the side in contact with the solid substance ; 
Darwin, to the endeavour to avoid the light. L. Kny has attempted 


* Linnea, xliii. (1881) pp. 139-252 (1 pl.). 

+ Magyar Novenyt. Lapok, v. (1881) pp. 151-6. 

{ SB. Bot. Vereins Prov. Brandenburg, xxiii. (1881). See Bot. Centralbl., ix. 
(1882) p. 10. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. BY is) 


to determine this question experimentally, by immersing pollen-grains 
in a mixture of gelatine (first warmed) and a solution of sugar, with a 
very small quantity of extract of meat, in which nutrient fluid they 
readily put out their tubes. He finds that neither the spot to which 
the pollen-tube attaches itself, nor the direction which it afterwards 
takes, nor the rapidity of its growth, is in any way affected either by 
gravitation or by light, or by contact with a solid substance. Similar 
experiments on four fungi, Mucor Mucedo, M. stolonifer, Trichothecium 
roseum, and Hurotium repens, yielded similar results as far as gravi- 
tation was concerned, this force appearing to exercise no influence on 
the direction or rapidity of growth of the mycelial filaments, nor on 
their branching. 


Water Distribution in Plants.*—G. Kraus having expressed 
and filtered the sap of Lonicera tartarica and Datura, and taken 
the specific gravity with the usual precautions, found it varied 
between 1:03 and 1:0059. The juice of sugar-beets ranged 
between 1:057 and 1:074. The specific gravity of the sap in the 
growing twig was found to be less in the older than in the younger 
portions, and growth was invariably accompanicd by dilution of the 
sap, owing to constantly increasing absorption of water. The free 
acids and albumen also decreased in percentage, but increased in 
actual quantity. The increase in sugar during growth was remarkable ; 
it increased with great rapidity up to a certain point, when it again 
declined, so that there is a maximum point in sugar contents, which 
is not at all coincident with the maximum of growth. 

An extended series of observations shows that in crooked plants 
the under or convex side contains sap of less concentration, and 
poorer in free acid and sugar, not only relatively, but absolutely. 
Horizontal branches are richer in sugar than vertical. When plants 
are shaken so as to bend their tops towards the ground, an immediate 
increase of specific gravity in the sap, and an increase of sugar in the 
under or convex part of the bend takes place, showing that the sugar 
is in actual process of formation at the time of bending. 


Causes of the Movement of Water in Plantsj—J. Boehm 
adduces experimental evidence in favour of his theory, already pub- 
lished, that the main factor in causing the motion of water in plants 
is not osmose, but the unequal pressure in different cells caused by 
the constant variation in the intensity of transpiration. 


“ Compass-flowers.”’ {—H. Stahl gives the results of his experi- 
ments with Lactuca Scariola and Silphium laciniatum for the purpose 
of ascertaining the conditions which cause their leaves to assume a 
meridional position. In the case of Silphiuwm, the common “ Compass- 
plant” of the Western States of America, the fact that the leaves 
point in a north and south direction has long been known, but in 


* Bied. Centr., 1881, pp. 630-2. Journ. Chem. Soc., xlii. (Abstracts), 1882, 
p. 327. See also this Journal, iii. (1880) pp. 294-5. 

+ Bot. Ztg., xxxix. (1881) pp. 801-13, 817-27. 

t Jen. Zeitschr. f. Naturw., xv. (1881) pp. 381-9 (1 (pl.). Cf. Amer. Journ, 
Sci., iii. (1882) pp. 159-60. 


374 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Lactuca Scariola, although it had been observed that the leaves were 
often vertical, Stahl was the first to notice that they generally stood 
in a meridional plane. 

In both plants, the peculiar position of the leaves is best seen 
when they grow in unsheltered places, exposed to bright sunlight ; 
while when crowded together, or growing in the shade, the leaves 
generally assume the common horizontal position. The leaves of 
Lactuca ou the north side of the stem become vertical by a twisting 
of the petiole, the upper surface of the leaf facing the east. Those 
on the south side by a similar twisting become vertical with the 
upper surface facing the west. The leaves on the east and west side 
of the stem do not exhibit any torsion of the petioles, but they become 
upright with their upper surfaces approximated to the stem. Stahl 
took two plants growing in pots, and placed one where it would be 
exposed to direct sunlight from 10 o’clock until 3, and kept in the 
dark for the rest of the day ; the other was placed so that from sun- 
rise until 10 o’clock, and from 3 o’clock until sunset, it was exposed 
to the sunlight, but from 10 to 3 was in the dark. In the first case’ 
the leaves did not assume a meridional position, but in the second 
case they did. 

That the meridional position is produced by the sun when near 
the horizon is clearly shown by the following experiment:—A_ pot 
with several young plants was placed in a window facing the north, 
where the plants received direct sunlight a few hours after sunrise 
and before sunset. In this experiment the leaves bent towards the 
north with their upper surfaces turning either to the east or to the 
west. The pot was then placed farther back in the room, so that 
the plants were not exposed to the direct sunlight, and the leaves 
then assumed a position at right angles to the diffused light from the 
window. Stahl concludes that the meridional position of the leaves 
of Lactuca Scariola is due to the common diaheliotropism observed in 
most leaves, and that these leaves differ from those of other plants 
only in their greater sensitiveness to intense light. In Silphium 
there is a torsion of the petioles as in Lactuca; and if the petioles 
are fastened so that they cannot bend, the blade of the leaf itself 
twists. Stahl states that a meridional position of the leaves can be 
seen clearly in Aplopappus rubiginosus, and to some extent also in 
Lactuca saligna and Chondrella juncea, and he believes that many 
other examples will be found, especially among the plants of dry and 
exposed regions. 

B. CRYPTOGAMIA. 


Cryptogamia Vascularia. 


Relation of Nutrition to the Distribution of the Sexual Organs 
on the Prothallium of Ferns.*—K. Prantl has made a series of 
experiments on the influence of different nutrient solutions on the 
development of the sexual organs on the prothallium of ferns, especially 
Osmunda regalis and Ceratopteris thalictroides. The following are the 
principal results at which he has arrived :—1, A deficiency of nitrogen 


* Bot. Ztg., \xxix. (1831) pp. 753-8, 770-6. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. o15 


is prejudicial to the formation of meristem; 2. Access of nitrogen 
will induce an amerismatic prothallium to pass over into a merismatic 
condition. 

The development of the reproductive organs on the prothallium 
is closely connected with its nutrition. Amerismatic prothallia 
produce antheridia only, never archegonia; these latter organs being 
produced only in the neighbourhood of a meristem. 

The author regards those prothallia of ferns which produce 
archegonia only and no antheridia as exhibiting the first step in the 
advance from the isosporous to the heterosporous Filicinez. 


Cell-division and Development of the Embryo of Isoétes lacustris.* 
—Hofmeister formulated the general law that in cell-division each 
newly formed division-wall stands at right angles to the direction of 
the preceding most energetic growth. Sachs disputed this view; 
but Dr. F. Kienitz-Gerloff supports the previous view of Hofmeister, 
adducing as evidence the following instances:—The processes of 
division in filaments of Cladophora, especially in the formation of 
lateral branches; the division in the apex of a shoot of Metzgeria ; 
the processes in the apical cell of a young rudiment of the sporo- 
gonium of Archidium phascoides, which divides by walls inclined in 
two opposite directions ; the cone of growth of Salvinia exhibiting a 
similar structure ; the breaking up of the apical cell of Cladostephus, 
on the cessation of growth at the apex at the commencement of the 
dormant season; the development within the apical cell in older 
prothallia of ferns and in embryos of mosses, which determines the 
direction of the division-walls; the formation of the cap-cells and of 
seginents in roots with a three-sided pyramidal apical cell; as also in 
segment-cells generally. 

The interior of the macrospore of Isoétes lacustris is occupied by 
moderately large roundish cells, each having a nucleus; no dia- 
phragm, like that of Selaginella, could be detected. Older unfertilized 
prothallia had from twenty to thirty archegonia. The first division- 
walls in the embryo divide it into octants. The cotyledon is formed 
out of the two anterior and upper octants; the first root out of the 
two posterior and upper ones; the foot out of the four lower octants. 
The further cell-divisions are followed out in detail. 

The examination of the ripe and half-ripe spores is attended with 
great difficulty; the author has not found any hardening material 
adequate for obtaining good sections, and at the same time giving 
sufficient clearness to the preparation. Soaking fora time in glycerine 
answered for certain purposes. 


Muscinee. 


Chemical Composition of Mosses.{—E. Treffner has investigated 
the chemical composition of several species of moss. He finds the 
amount of silica always high, and varying but little in different 
species ; the greatest quantity was found in Funaria. Orthotrichum 

* Bot. Ztg., xxxix (1881) pp. 761-70, 785-95 (1 pl.). 

+ E. Treffner, ‘Beitrage zur Chemie der Laubmoose,’ 62 pp., Dorpat, 1881. 
See Bot. Centralbl., ix. (1882) p. 9. 


ae SUMMARY OF CURRENT RESEARCHES RELATING TO 


and Dicranum are distinguished by, containing a large amount of oil. 
Mnium contains 10 per cent. of sugar; the proportion decreases 
successively in Climacium, Polytrichum, Hypnum, Dicranum, Sphagnum, 
Orthotrichum, Schistidium, and Ceratodon. Albumen occurs abundantly 
in the protoplasmic cells of the leaves; Ceratodon purpureus contains 
12, Polytrichum 5 per cent.; but it is not in a condition serviceable 
for the nutrition of animals. 


Fungi, 


Influence of Oxygen on the Development of the Lower Fungi.* 
—F. Hoppe-Seyler states, as the result of a careful series of experi- 
ments, that an excess of oxygen greatly promotes the development of 
bacteria and micrococci, while it exerts a retarding influence on the 
production of yeast and true ferments, hindering fermentation by the 
transformation of the organic substances which ordinarily result from 
it, by active oxidation, into carbonic acid, water, and ammonia. 


Chetomium.{—W. Zopf has followed out the life-history of this 
ascomycetous fungus, especially in the instance of C. kunzeanuwm. 
The ascospores germinate readily in saccharine vegetable juices, 
solution of sugar, decoction of dung, urine, and even in water. In 
addition to the mycelium formed in the substratum, there is generally 
an aerial mycelium, often of great luxuriance. The formation of 
perithecia begins after a few days, commencing in the centre of the 
mycelium, and advancing centrifugally. ‘They proceed from both the 
submerged and the aérial mycelium, originating in the form of short 
erect branches, with dense and strongly refractive contents. The 
primary hyphe now branch repeatedly, bending and interlacing, and 
thus producing a dense ball. No differentiation of ascogenous and 
enveloping hyphe can be detected, as in other Ascomycetes. In the 
centre of this pseudo-parenchymatous mass of hyphe is formed a 
hollow, into which the adjoining cells send down tubular septated 
projections, the “nucleophyses”; this results in the first and most 
important differentiation, into the peripheral part or perithecial wall 
and the central portion or nucleus. The nucleophyses, which corre- 
spond to the base of the perithecium, now undergo a more energetic 
development in comparison to the rest, being not only longer, but 
branching more copiously, forming a pseudo-parenchymatous cushion, 
on the outermost branches of which, projecting into the perithecium, 
are produced the asci, and, since all the terminal branches are fertile, 
there are no paraphyses. The hyphe which clothe the lateral walls 
of the perithecium, branch but little, and remain sterile, may 
be termed “ periphyses,” those that constitute the ascogenous cushion 
“ascophyses.” The wall of the perithecium becomes differentiated into 
an outer layer composed of narrow brown cells with slightly thickened 
walls, and an inner layer composed of thin-walled turgid cells. 
About the time when the asci are being developed, a mouth is formed 


* F, Hoppe-Seyler, ‘Ueber die Einwirkung des Sauerstoffs auf Gahrungen,’ 
32 pp., Strassburg, 1881. 

+ Nova Acta Acad. Leop,-Carol., xlii. (1881) (7 pls.). See Bot. Centralbl., 
ix. (1882) p. 258. ‘ 


ZOOLOGY, AND BOTANY, MICROSCOPY, ETC. Old 


at the apex of the cavity concealed by a dense funnel-shaped coating 
of hairs. The spores are produced eight in each ascus; the asci 
themselves and the periphyses deliquescing into a jelly, the swelling 
of which forces the numerous spores out through the opening. 

If the nutriment is insufficient, small flask-shaped projections 
are formed on the mycelium, from the swollen ends of which are 
abstricted ellipsoidal or obovoid cells in basipetal succession ; and 
these conidia may form balls which remain permanently attached to 
the apex of the sterigmata; but they, as well as those which may be 
produced on other parts of the mycelium, appear to have lost their 
power of germination. 

Similar results were obtained from other species; but C. fimeti 
has no opening to the perithecium, and C. bostrychodes forms no 
conidia. 

With regard to the systematic position of Chcetomium, it differs 
. from other genera of Ascomycetes, as Hurotium, Erysiphe, Penicillium, 
- Sordaria, and Ascobolus, in the absence of any distinct differentiation 
of the rudimentary fructification into ascogenous and enveloping 
hyphe, agreeing on this point with Peziza Fuckeliana and Pleospora 
herbarum.  Peziza is, however, a gymnocarpus Discomycete; and 
from Pleospora, Chetomium differs in the perithecium originating not 
as a tissue but as a mass of hyphe, and in the process of differentia- 
tion of the fructification. Chetomium must therefore be regarded, 
like Pleospora, as a special type of Pyrenomycetes. Since the Peri- 
sporiacez have perithecia closed on all sides and without any opening, 
while Chetomium resembles the Spheeriacee in having such an open- 
ing, it is evident that the boundary line between the Perisporiacez 
and the Spheeriacez is not so sharp as has generally been supposed. 

Zopf divides the genus into two subgenera:—(1) Euchetomium ; 
—perithecium with terminal tuft of hairs and an opening (C. spirale, 
murorum, pannosum, crispatum, bostrychodes, kunzeanum, cuniculorum, 
indicum, and elatum); and (2) Chetomidium :—perithecium without 
any opening or terminal tuft of hairs; furnished at its base with 
thick wiry rhizoids (C. fimeti). Several of these species are new. 


Completoria complens, a Parasite on the Prothallium of 
Ferns.*—This fungus has been found by Leitgeb on the prothallium 
of Pteris cretica and other ferns, and even, in some cases, on the 
leaves. It penetrates the host from without in the form of a spherical 
cell, which attaches itself by a stalk-like prolongation to the outer 
wall of the cell of the host, occupying about the centre of the cell- 
cavity. The contents consist of finely granular protoplasm, the wall is 
extremely delicate, and the pedicel is usually enclosed for half its 
length in a dark-brown sheath. It then puts out a number of pro- 
longations which penetrate the adjacent cells. The reproductive 
cells are of two kinds, conidia and resting cells; the formation of 
zoospores seems probable, but has not yet been observed; the resting 
spores, which vary in diameter between 18 and 25 p, are formed 
especially when the supply of nutriment is insufficient. 

* SB. k. Akad. Wiss. Wien, Ixxxiv. (1881) (1 pl.). See Bot. Centralbl., viii, 
(1881) p. 226. 
Ser. 2.—Vou. II. 20 


378 SUMMARY OF CURRENT RESEARCHES RELATING TO 


As regards the systematic position of the fungus, Leitgeb con- 
siders that it may bear a similar relation to the Peronosporee to 
that of the Chytridiacee to the Saprolegniee; in both we have 
degraded forms in which the production of sexual organs has been 
lost, the resting spores taking their place. 


Rehm’s Ascomycetes.—This most valuable and important collec- 
tion of dried ascomycetous fungi has now reached twelve parts, and 
includes no fewer than 600 species, 281 belonging to the Discomy- 
cetes, and 319 to the Pyrenomycetes. Of these 59 of the former and 
37 of the latter are new. The most recently published part contains 
detailed and exact descriptions of all these new species, as well as 
critical remarks on all the other species already included in the 
collection. 


Destruction of Insects by Yeast—In 1880 we called attention* 
to some experiments of Professor H. A. Hagen, of Cambridge, Mass., 
the results of which showed (he considered) that the yeast fungus 
entered the body of the insect on which it was sprinkled, and pro- 
duced a growth fatal to the life of the insect. Professor Lankester, 
however, at the time pointed out that the more probable explanation 
was that the yeast fungus itself was innocuous, but that it was a vehicle 
for such a parasite as “ green muscardine ” (Isaria destructor), which 
Metschnikoff found was best cultivated by the use of beer-mash. 

Mr. T. H. Hart, of Ashford, having tried the application of yeast, 
reports t to Professor Hagen that while a first experiment was 
successful all subsequent ones failed, and he feared therefore that 
yeast is too uncertain in its application to be of practical use. To 
this Professor Hagen replies as follows :— 

“Tt seems evident that the yeast has not contained Isaria or 
other fungi obnoxious to insects to which the first success could be 
ascribed ; otherwise the later application of the same fluid ought to 
have had the same effect, or even by the multiplication of the fungi 
a more marked effect. 

“Experiments made in Germany and here (U.S.A.) had exactly 
the same result—first success, later failure. . . . After all, I 
believe it can be concluded that a certain stage of the yeast solution 
is needed to make it effective, and that after this stage it becomes in- 
different. That yeast solution has killed insects seems to be un- 
doubtedly proved, and it remains only to find out the stage in which 
its application is successful. It is sure that success, even in a very 
small number of experiments, cannot be annihilated by failure in 
other experiments.” 


Development of Fungi on the Outside and Inside of Hens’ 
Eggs.t—C. Dareste put an egg (for artificial incubation) in a 
vessel hermetically closed by an indiarubber stopper, and of small 
capacity (about 0°35 litre). On the sixth day the egg was covered 
with green spots of fructified mould; then there appeared on the 


* See this Journal, iii. (1880) pp. 246-8. 
+ Canadian Entomologist, xiv. (1882) pp. 38-9. 
t~ Comptes Rendus, xciy. (1882), pp. 46-9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 379 


shell white filaments of mycelium, which in their turn soon showed 
fructification. When the egg was opened, some days afterwards, 
a tolerably thick layer of mycelium was found adhering to the shell- 
membrane. There was no trace of an embryo. Experiments with 
sixty eggs having the same origin gave only three entirely free from 
the cryptogamic vegetation. In several the embryo had begun to 
develope, and had been destroyed in the course of the first week. 
There were also in all the eggs considerable masses of mycelium, 
usually occupying certain points on the internal surface of the shell 
membrane, but, in certain cases also, floating in the albumen or rami- 
fying inthe yolk. When this mycelium was produced in the region 
of the air-chamber, the cavity was filled with fructifying green 
mould. The moulds were of several species (often co-existent), the 
most frequent being Aspergillus. 

The author then considers the origin of these growths, and 
whether they ought to be attributed to the germination of spores 
adhering to the walls of the vessels used in incubation, or contained 
in the air inside them; to spores deposited on the shell during the 
interval between laying and incubation ; or to spores enclosed in the 
egg itself before the completion of its formation in the oviduct ? 

Numerous experiments have led M. Dareste to doubt the two 
former explanations, he having heated the vessels which were to 
contain the eggs to 120° C. in order to kill any spores, and at other 
times used the spray of carbolated water ; the vegetation nevertheless 
developed as abundantly as before. He therefore supposes that the 
spores were enclosed in the egg at the time when the yoke becomes 
covered in the oviduct with layers of albumen. 

As, however, the methods used to destroy the spores are open 
to objection, he would not consider the latter to be the most probable 
hypothesis, did not other experiments point to it. The eggs used 
in the first experiments all came from the same locality (Seine-et- 
Oise). A batch of eggs from the department of Vienne, however, 
only had three infected eggs, and eight which were exempt. Eggs 
from the departments of the Oise and the Eure were experimented 
on at the same time as those from the Seine-et-Oise, and the latter, at 
the expiration of twelve days, had five eggs infected out of six. On 
the other hand, six eggs from the Eure had only two infected. The 
seven eggs from the Oise were, on the contrary, perfectly intact. 
This difference between eggs placed in absolutely identical conditions 
can only be explained by the inclosure of the spores in the eggs, in 
the oviduct, and before the formation of the shell. It shows also 
that the cause which infects the eggs is essentially local. 

Gayon has demonstrated the mechanism of thisinfection. He has 
shown that the prolapsus of the oviduct, at the moment of copula- 
tion, places its mucous membrane in contact with that of the cloaca, 
and also with that of the cloaca of the cock. The oviduct, in resuming 
its original position, draws in with it the microbia and all the 
foreign bodies which it may find in these cavities. These circum- 
stances are similarly produced at the moment of laying. The 
existence of foreign bodies in the interior of eggs has also often 

Pag 


380 SUMMARY OF CURRENT RESEARCHES RELATING TO 


been proved. M. Dareste recently observed that there were in the 
albumen of an egg some pellicles of bran perfectly recognizable by 
their structure, and by the considerable number of starch-grains 
which they contained ; these pellicles were quite 1 mm. in diameter. 
The diameter of the spores can only be reckoned by thousandths of 
a millimetre. 

In the experiments above described the eggs were in an atmo- 
sphere completely saturated with humidity in consequence of the 
insensible transpiration of the egg, but even in the ordinary condi- 
tions of incubation the spores enclosed within it may germinate, and 
the greater or less abundance of the vegetation may completely pre- 
vent the development of the embryo or arrest it after it has begun. 
This is one of the principal causes of the premature death of the 
embryo, and also of the inequalities constantly observed in the results 
of incubation. 


Biology of Bacteria.*—During his researches on bacteria as 
reagents for the physiological disengagement of oxygen,t T. W. 
Engelmann had occasion to examine whether light could exercise 
a direct action on the movements of the bacteria. Nothing had at 
that time suggested such an influence. Experiments had been made 
on the ordinary bacteria of putrefaction (B.termo). The temperature, 
the tension of the oxygen, the proportion of carbonic acid, the con- 
centration of the medium, the intensity, the colour and duration of 
action of the light had been modified in very different ways. 

Later on, whilst repeating these same experiments on Vibrios and 
Spirilla, the author also obtained negative results, with one single 
exception. 

A drop of water, which, besides a quantity of Spirillum tenue, only 
contained a few specimens of Micrococcus and a Bacterium of larger 
size (2-3 ,) being illuminated over a very small portion of its 
surface, there collected in less than half a minute,t at the illuminated 
spot, hundreds of Spirilla and, besides, some of the little cocci and 
larger bacteria. In the dark, and even in green or blue light, they 
re-distributed themselves, but not in the red light, even where it was 
of relatively feeble intensity. It may be presumed from this fact 
that there was a disengagement of oxygen, for when the gas failed 
them, the organisms in question accumulated round every source of 
oxygen (air-bubble, edge of the glass, cover-glass, and green cells) 
which was accessible to them. 

The accumulation of Spirilla and bacteria at the illuminated spot 
did not take place when the drop of water was uncovered and in 
continuous contact with the atmospheric air or with a mixture of 
hydrogen and oxygen. They accumulated, however, as soon as a 
current of pure hydrogen was passed through the gas-chamber, to 
disappear again almost immediately as soon as a little oxygen was 
allowed to enter. 

* Rey. Internat. Sci., ix. (1882) pp. 276-8. See also Bot. Ztg., xl. (1882) 
pp. 321-5, 337-41. t+ See this Journal, i. (1881) p. 962. 


¢ At least when the preparation had remained for some minutes covered with 
a thin glass. 


. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 381 


As the Spirilla greatly predominated, as much in number as in 
volume, the author had at first considered it probable that it was 
they which disengaged oxygen under the influence of light. But 
Spirilla, even in thick layers, are quite colourless. We should, there- 
fore, have here the unheard-of fact of a disengagement of oxygen 
without the agency of chlorophyll or of some pigmentary matter of 
equivalent function. This would demand extreme scepticism. 

Later researches have shown that the Spirilla only approach the 
light when the drop also contains the larger bacteria mentioned above. 
The latter appeared constantly, although in very small numbers, at 
the illuminated spot, before the accumulation of the Spirilla began. 
On examining these bacteria with a high power and a good light, it 
was seen that they were of a greenish colour, but less intense, how- 
ever, than that of most chlorophyll-grains of the same size. The 
author gives them the name of Bacterium chlorinum. They are not 
identical with B. viride and Bacillus virens of Van Tieghem, which 
are motionless forms. Bacterium chlorinum has, in a high degree, the 
tendency of accumulating in the light, but only when oxygen is 
absent. It is a property it shares with some other green micro- 
organisms, for instance, with Paramecium bursaria. 

These results make it very probable that the accumulation of 
Spirilla, cocci, and bacteria, in the light, described at first, was the 
consequence of the disengagement of oxygen produced by the Bac- 
terium chlorinum assembled in the illuminated spot. This explanation, 
however, only seems acceptable on the supposition that the Spirilla 
only required very little oxygen, much less than the ordinary bacteria 
of putrefaction, although they are much smaller. 

To verify this supposition, the author has examined the behaviour 
of Spirilla under different tensions of oxygen. He found that in 
hydrogen gas as free as possible from oxygen, and even under a plate 
of glass with hermetically closed edges, they move rapidly many 
hours after the motion of the bacteria of putrefaction has ceased. 
Covered with a piece of glass, the Spirilla do not accumulate, like 
Bacterium termo, at the very edges of the cover, but at some distance 
under the glass. If the tension of the oxygen diminishes in the gas- 
chamber this distance decreases ; if the tension increases the Spirilla 
retire further. Similar phenomena are observable under the glass 
cover, around air-bubbles, and green vegetable cells, living and 
exposed to the light. When the latter are strongly illuminated the 
zone of Spirilla ceases at a certain distance from them, parallel to 
their surface ; it approaches when the luminous intensity diminishes, 
and vice versa. 

There is therefore no doubt that the tension of oxygen most 
favourable for Spirilla is not much lower than for Bacterium termo. 
It is certainly less than 150 mm. Hg., and may be considerably less. 
The Spirilla re-act at relatively very slight variations of the tension 
of oxygen. In these respects they behave like certain Flagellata (i.e. 
Monas termo) and Ciliata (Glaucoma scintillans), which develope by 
preference in putrefying liquids. 

Vibrios—which, according to the author, cannot be sirictly 


382 SUMMARY OF CURRENT RESEARCHES RELATING TO 


separated morphologically from Spirillum, Bacillus, and Bacteriwum— 
also behave, as regards the tension of oxygen, almost exactly like 
Spirillum and not like Bacterium termo. 

The author regards* Spirillum as remarkably sensitive to the 
presence of free oxygen; and he considers that the vital phenomena 
of both the lowest vegetable (Schizomycetes) and the lowest animal 
forms (Infusoria) are closely parallel to those of higher animals ; their 
activity being dependent, in almost the same degree, on their require- 
ments of oxygen and of solid and liquid food for carrying on their 
vital processes. 


Influence of Concussion on the Developments of the Schizo- 
mycetes.t—J. Reinke has determined, by a careful series of experi- 
ments, that mechanical concussion produces a hindering effect on the 
production of Schizomycetes. He believes the cause to be the same 
as that of the retarding influence of light, viz. the concussion occa- 
sioned between the minute particles of protoplasm. 


Experimental Production of the Bacteria of the Cattle- 
distemper.{—C. v. Nigeli has carried out a series of experiments on 
the conditions under which the bacteria are produced which accom- 
pany the distemper of cattle. The most important fact established is 
that these bacteria are capable of transformation into a transitional 
form which may constitute a pellicle on the surface of the nutrient 
fluid, possessed of spontaneous motile properties, and which has a 
very slightly infectious character; constituting a transitional stage 
towards the hay-bacteria. The following is a tabular arrangement 
of the characters of the three primary forms, when grown in three 
different substrata. The author is strongly of opinion that these 
three fungi are simple adaptive forms of one and the same organism, 
Bacterium subtile. 


Distemper-bacteria. Transitional Form. Hay-bacteria. 


1 p. cent. extract Solution clear | Solution cloudy, a loose Solution clear, with a 


of meat. | cloudy at the mucilaginous pellicle; solid dry white pelli- 
bottom. flakesand piecesofthe cle, submersed with 
pellicle at the bottom.) difficulty. 

Slightly acid No increase. Formation of a slight A dry pellicle moist- 

infusion of hay. white rim on the sur- ened with difficulty, 

face of the fluid. usually appearing 
wrinkled or pulveru- 
lent. 

A living animal. Infectious in Infectious only when Not infectious in the 
very small increased more than) largest quantities. 
quantities; dis-| a thousand-fold; dis- 
temper. | temper. 


* Pfliiger’s Arch. f. d. gesammte Phys., xxvi. (1881) pp. 537-45. 
+ Ibid., xxxiii. (1881) pp. 443-68. See Bot. Centralbl., viii. (1881) p. 307. 
¢ SB. Akad. Wiss. Miinchen, 1882, pp. 147-69. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 383 


Bacteria of Caucasian Milk Ferment.*—E. Kern describes a new 
genus and species of bacteria found in “kephir,” a drink prepared by 
the inhabitants of the high-lying lands in the Caucasus by fermenta- 
tion of cows’ milk. It is also used as a remedy against different 
diseases. 

As a ferment in its preparation strange white lumps are em- 
ployed, of a spherical or elliptical shape, in size from 1 m. to 5 em. 
Microscopical examination showed that they consisted of yeast-cells 
and bacteria. The yeast-cells are the ordinary form, produced by 
cultivation, of Saccharomyces cerevisie, but Kern was unable to get 
these to the spore-bearing stage. The bacteria composed the chief 
part of the lumps, and were in the zooglcea state. The vegetative 
bacteria cells were 3:2 m. to 8 m. in length and 0-8 broad. In prepa- 
rations put up by drying, a distinct cell-membrane could be dis- 
tinguished. 

Treated after Koch’s method, the cells show at one end a loco- 
motive organ, which resembles a cat-o’-nine-tails of threads. When 
exposed to acids or a high temperature, the cells grow out, 
probably through progressive cell-divisions, into long Leptothrix 
threads, which change generally precedes the spore-formation stage. 
The spores are round, always formed in twos in each cell, and are 
always placed standing on their ends; even by a Hartnack immersion 
X, no partition-wall could be discovered between the spores. In the 
Leptothrix-threads rows of spores could be observed, which are, 
however, always so situated that two spores belong to each cell. 
The spores while still in the cells are 0:8 in size; those lying free 
attain the size of 1; the germinating spores swell up 1-6 p. 
The germination of the spores generally takes place in such a 
manner, that an exosporium and an endosporium can always be 
distinguished in them. The thinner endosporium arises out of the 
thicker exosporium, first as a small excrescence, which gradually 
increases, developing more and more into a long cylindrical tube, 
and then begins by cell-division to form vegetative cells. The 
whole course of the development to the spore formation, beginning 
with the vegetative cell to the formation of a similar new cell, was 
followed. 

This new form of bacteria, which undoubtedly belongs to the 
Desmobacteria of Cohn, is, in its vegetative state, not unlike Bacillus 
subtilis ; it is, however, clearly distinguished not only from it, but 
also from all other kinds of Bacteria by its spore formation, since 
it always forms in each cell two round spores, placed end to 
end, while in the species of Bacteria hitherto described, only one 
spore has been noticed in each cell. On account of this sharply 
marked feature Kern places this form of Bacteria in a new genus, 
next to Bacillus, and calls it Dispora caucasia noy. gen. et sp. 

A more exhaustive essay on the subject, with explanatory plates, 
Kern promises in a forthcoming number of the ‘Bulletin de la 
Société Impériale des Naturalistes de Moscou.’ 


* Bot. Ztg., xl. (1882) pp. 264-6. Cf. Nature, xxvi. (1852) p. 43. 


384 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Parasitic Organisms of Dressings.*—The dressings of wounds 
sometimes acquire a blue or green colour. C. Gessard finds this to 
be due to a small mobile parasitic organism which he was able to 
cultivate in sterilized urine or a decoction of carrots. It is developed 
in saliva, sweat, albuminous liquids, &c. The blue pigment it 
secretes is the pyocyanine of Fordos. A current of sulphuretted 
hydrogen turns it green and then yellow, and the organism has the 
same action by reason of its avidity for oxygen. 


Parasitic Nature of Cholerat——Max v. Pettenkofer argues in 
favour of the origin of cholera from parasitic organisms. These 
organisms he believes to be propagated by intercourse with places in 
which the disease is epidemic or endemic; but that, when removed to 
another place, without losing their poisonous properties, they propagate 
themselves only when they find at this place a substratum which serves 
as their nutrient or as host, and which comes into contact with man 
either directly or in the soil of their dwellings. Even where cholera 
breaks out apparently without any connection with the soil, as in 
ships, he believes the germ comes into contact with the substratum 
brought from the land. The only effectual remedy for cholera he 
believes to be the purifying of the soil by drainage, &c., the 
ventilation of dwellings, cutting off of infected water, and similar 
means. 


Parasitism of Tuberculosis.}—H. Toussaint collected in a care- 
fully cleansed vessel the blood from a cow affected with tuberculosis, 
allowed it to coagulate, and transferred the serum which separated 
after coagulation into some Pasteur’s tubes filled with infusion of 
the flesh of cats, swine, and rabbits, and placed them in a warm 
chamber. After a few days there were formed in these fluids very 
small simple granules, united into pairs or in masses. From these 
was made a second culture with which kittens were infected, but 
they died before tuberculosis manifested itself. Five months after- 
wards he inoculated two older cats from the remaining serum, which 
still showed the globular granules. These died 47 days after inocula- 
tion; one exhibited a moderately conspicuous local lesion, and a 
considerably swollen axillary gland, but no tubercles in the lungs ; 
the other, similar lesions, as well as of the lymphatic glands, and a 
number of minute tubercles scattered through both sides of the 
lungs. A second culture from the blood of a cow affected with 
tuberculosis must be regarded as having failed, since the greatest 
variety of microbia made their appearance. On the Ist of March he 
killed a pig which had been fed with the lungs of a tuberculose cow, 
containing a great number of tubercles, and in which all the 
lymphatic glands were cheesy. Blood and the pulp from the 
lymphatic glands were mixed with a slightly alkaline infusion of 


* Comptes Rendus, xciv. (1882) pp. 536-8. 

+ Zur Aetiologie der Infectionskrankheiten, 1881, pp. 333-52. See Bot. 
Centralbl., ix. (1882) p. 25. 

{~ Comptes Rendus, xciii. (1881) pp. 350-3. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 385 


the flesh of rabbits, which they soon rendered turbid, all developing 
the same microbium. The cultures, which were continued up to the 
tenth, completely retained their purity. After ten or twelve days 
they always ceased to increase, the exhausted fluid became clear, and 
the microbia fell to the bottom, forming a yellowish sediment. 
This sediment consisted entirely of extremely minute granules, 
which were produced singly or in pairs, groups of from three to 
ten, or in small irregular masses. During the early days of the 
culture white spots appeared, resembling the filaments of bacteria, 
which could be sucked up through a fine tube. They remained for 
some days in the clear fluid without becoming absorbed, the 
microbium being at this time enclosed in a somewhat firm mass of 
mucilage. 


Experimental Tuberculosis.*—D. Brunet records experiments 
on inoculation with tuberculosis made in 1869 on rabbits. Nine- 
teen young rabbits were infected, seven with serum from a cancer, 
six with serum from an ordinary ulcer, and six with tuberculose 
matter. Of the nineteen, fourteen became tuberculose, the remaining 
five escaped. Since infection with cancer-serum produced tuber- 
culosis as often as infection with tuberculose matter, he thought it 
probable that the infecting mass itself produced no specific action, 
but that it behaved as a foreign body, causing inflammation around 
it, and that this gave rise to tuberculosis. Since the matter from 
ordinary ulcers was more easily absorbed than solid matter, it 
produced a smaller degree of inflammation, and hence gave rise less 
often to tuberculosis. 


Etiology of Tubercular Disease.t—The circumstantial evidence 
that tuberculosis is a chronic infectious disease has been of late years 
repeatedly insisted on by Cohnheim and others, and the hypothesis 
that it is due to a specific organism has received considerable support 
from the discovery of parasitic elements as the materies morbi of some 
other chronic infectious diseases, such as leprosy. But the organism 
of tubercle has hitherto eluded research. Its discovery is at last 
announced by the distinguished worker to whose investigations 
much of the progress of bacterial pathology has been due, Dr. R. 
Kochs 

It is only by means of a special method of preparation and ex- 
amination that the bacteria can be detected. The method consists 
essentially in a process of colouring the organisms, and their exami- 
nation under very strong illumination ; but the details of the method 
have to be varied according to the tissue examined, whether a secretion, 
blood-tissue fluid, or a section of an organ or tissue. If, for instance, 
it is desired to demonstrate the presence of the tubercle-bacilli in the 
fluid of the tissues, a thin layer of this is spread over a cover-glass, it 
is then dried and warmed for a few moments over a flame, so as to 


* Comptes Rendus, xciii. (1881) pp. 447-8. ‘ 
+ Verh. Physiol. Gesell. Berlin, 1882, p. 65. Lancet, 1882, pp. 655-6. 
Naturforscher, xv. (1882) pp. 149-90. 


386 SUMMARY OF CURRENT RESEARCHES RELATING TO 


render it insoluble; it is then placed for twenty-four hours in a 
mixture of 1 cubic centimetre of a concentrated solution of methylene- 
blue in alcohol, 0:2 cubic centimetres of a 10 per cent. solution of 
potash, and 200 cubic centimetres of distilled water. The preparation 
is by this coloured blue, and on it is then placed a few drops of a 
solution of vesuvin. This has the effect of discharging the methylene- 
blue from all the tissue elements, but not from the bacilli. The 
former are of a brown colour, and the blue bacilli are conspicuously 
defined. The preparation is then treated with absolute alcohol, oil of 
cloves, and Canada balsam, in the ordinary manner. This peculiarity 
of being rendered visible by the combined action of methylene blue 
and vesuvin is possessed only by the tubercle bacilli and by those of 
leprosy. All other bacteria and micrococci, known to Koch, lose, 
under the action of vesuvin, the blue colour which they acquire from 
methylene-blue. This constitutes a striking instance of the pregnant 
value of the colouring methods in thus, by quasi-chemical action, 
bringing out differences between minute organisms which are appa- 
rently so similar, and justifies the expectation that, by analogous 
means, differences may be demonstrated between the organisms of 
acute diseases which are now separable with so much difficulty and 
uncertainty, and may be the inauguration of a new era, not only in 
the etiological knowledge of acute diseases, but also in the organization 
of measures for their prevention. 

The bacilli of tubercle, when rendered visible by this method of 
double coloration, are seen as very small rods, in length about one- 
third the diameter of a red blood-corpuscle, and in breadth about one- 
sixth of their length. In some of them distinct spores may be seen, 
as minute, unstained, refracting, vacuole-like structures, distinguish- 
able, however, from the vacuoles in that at their position there is a 
slight fusiform enlargement of the bacillus. They are most abundant 
in recent tubercular neoplasms, and least numerous in the caseating 
centre of old miliary tubercles. They are also visible within the 
giant cells, usually isolated, but sometimes forming well-marked sheaf- 
like bundles. Koch found the same organisms in the walls of tuber- 
culous cavities, in the sputum of phthisical patients, in degenerated 
scrofulous glands, in fungous joints, and in the bones of tuberculous 
cattle. They were never absent from the tubercular new formations 
produced by inoculation, even in animals of the most different 
species. 

In order to ascertain the all-important question whether these 
organisms are actually the materies morbi of tuberculosis, Koch has 
carried on an extensive series of culture-experiments, which have 
yielded the most striking results. As a culture-liquid he employed 
sterilized blood-serum from the ox. The sterilization was effected in 
the method recommended by Tyndall, by placing the serum in a test- 
tube closed with a plug of wadding, and exposing it for an hour on 
each of several successive days to a temperature of 58°C. After this 
had been repeated for about six days, the temperature was raised to 
65° C., and the previously fluid serum became transformed into a yel- 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 387 


lowish, translucent, but slightly opalescent mass of the consistence of 
coagulated gelatine. Its translucency permitted the growth of 
organisms, either on its surface or in its depth, to be readily recog- 
nized by the resulting opacity. In order to increase the area of the 
free surface of this culture soil, it is recommended to incline the test- 
tube at the moment of coagulation. A small fragment of excised 
tissue was introduced into a tube under special precautions, to avoid 
contamination with ordinary bacteria of putrefaction. Fresh miliary 
tubercle answers best, taken from an animal affected with inoculation- 
tubercle, and killed shortly before. If the glass is kept at a tempera- 
ture of 37° or 38° C., at the end of about ten days the first effect of 
culture is observable as fine white points and streaks on the surface of 
the serum. Fresh glasses may be inoculated from this first culture, 
and soa series of generations may be obtained. Some of these series 
of cultures were continued for two hundred days. Under the micro- 
scope these greyish-white masses on the surface of the serum are found 
to consist of precisely the same bacilli as can be demonstrated by 
means of the method of double coloration, in the primary tuberculous 
tissue. If a small portion is inserted into the anterior chamber of the 
eye of an animal, injected into its blood, or inoculated beneath its 
skin, there results a wide-spread tuberculosis of almost all the organs 
and tissues, which has a more rapid course than when the inoculation 
is made with ordinary tuberculous material. The first symptoms are 
to be observed in guinea-pigs ten days after the inoculation. Even 
animals which enjoy an almost complete immunity from tuberculosis, 
such as dogs and rats, are affected rapidly, and with certainty. In 
some of the animals which died after these inoculations, the amount 
of tubercle developed in the tissues was enormous, being hardly ever 
equalled in the human subject. 

Koch determines the limits of temperature between which the 
tubercle-bacillus can developeand multiply. The minimum temperature 
he finds to be 30° C., and the maximum 41° C. He concludes that, 
unlike the Bacillus anthracis of splenic fever, which can flourish freely 
outside the animal body, in the temperate zone animal warmth is 
necessary for its propagation. He also points to the grave danger of 
inhaling air in which particles of the dried sputa of consumptive 
patients mingles with dust of other kinds. 

These experiments seem to demonstrate that the organism which 
is revealed by the method of double coloration is really the patho- 
genic element of tuberculosis. The researches appear to have been 
conducted with admirable care. The experiment will no doubt be 
soon repeated. Indeed, in the brief interval which has elapsed since 
the demonstration by Koch, on March 24th, his observations have 
received independent confirmation by Baumgarten, who has published 
in the Centralblatt fiir Med. Wiss. an account of his observations. In 
every new formation of artificially produced tuberculosis in the 
guinea-pig he found innumerable quantities of the rod-shaped bacteria 
infiltrating the area in diminishing intensity from the centre to the cir- 
cumference. As far as the tubercular growth can be traced the 


388 SUMMARY OF CURRENT RESEARCHES RELATING TO 


bacterial infiltration extends. His description of the organisms agrees 
closely with that of Koch, but he observed that the extremities of the 
rods frequently presented a knob-shaped or wedge-shaped enlarge- 
ment. They were very rarely united in pairs, and never massed in 
the so-called zooglea form. He corroborates their characteristic of 
resistance to the ordinary methods of tinting, and only succeeded in 
bringing them into distinct view by dilute alkalies. In a postscript 
Baumgarten adds that he has succeeded in finding the same organisms 
in human tubercle. The pathological importance of the discovery of 
the proximate cause of this frightful scourge of the human race cannot 
be over-estimated, nor is it possible to foretell the practical results to 
which it may lead. 


Lichenes. 


Structure and Development of the Apothecia of Lichens,*— 
The well-known structure of the apothecium of lichens described by 
Stahl is taken from the Collemacez, where it is a product of an act of 
impregnation performed by the spermatia. The female organ or 
carpogonium here consists of two parts, a lower coiled portion, the 
ascogonium, and an upper multicellular filament, the trichogyne, 
through which impregnation by the spermatia takes place. After this 
process the trichogyne dies, and a fibrous tissue springs from the asco- 
gonium, composed of the asco-filaments which later develope into the 
asci; these are therefore the product of the fertilized ascogonium, 
with which the paraphyses have no direct connection. 

Since the Ascomycetes vary greatly in the mode of development 
of their fructification, it is to be expected that a similar variation 
should exist in the development of the ascogonium of lichens, espe- 
cially in those genera which do not possess a spermogonium. G. 
Krabbe has investigated this subject in detail, with special reference 
to the genus Sphyridium ; and the following are the main results 
at which he has arrived. The author throughout uses as synonymous 
the terms apothecium, fruit, fructification, and reproductive shoot. 

1. The genus Sphyridium exhibits a differentiation between the 
apothecium resulting from an entire scale of the thallus or from a part 
of one. The asco-filaments are the apices of ordinary hyphe, the 
cycle of development of S. carnewm terminating with their production, 
The production of the ascogonium is most probably independent of 
any act of impregnation. 

2. In Cladonia two morphologically different structures exercise 
the function of fructification in different species, viz. a, a pseudopo- 
detium or modification of the thallus; b, a podetium or new shoot com- 
plete in itself (carpophore). Both podetia and apothecia are of 
ascogenous origin. C. bacillaris and Papillaria are diccious. The 
following are the most important points regarding the power of 
producing shoots possessed by the apothecium. 

3. The apothecium of lichens possesses the property of putting out 
apothecial shoots at any spot, viz. a, from the hymenium, in Cladonia 
Papillaria and Lecidea Pilati ; b, from the periphery of the paraphysal 


* Bot. Zte., xl. (1882) pp. 65-83, 85-99, 105-16, 121-42 (2 pls.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 389 


tissue, or excipulum proper, in Pertusaria; c, from the hypothecium, 
in Phlyctis. ; 

4. From this power of producing shoots must be distinguished the 
division of the apothecium, by which, in Pertusaria, the isolated por- 
tions of the apothecium are produced, and in Gyrophora those 
chambers, each of which, separated from the others by a circular wall, 
must also be regarded as a thallus-apothecium. 

5. In Pertusaria no paraphyses are formed ; the asci are developed 
directly in the original tissue. 

6. In Phlyctis agelea the paraphyses begin to shoot while the 
asci are dying off, and thus again take part in the formation of the 
thallus. 

7. The apothecium of Phialopsis, at first entirely angiocarpous, is 
subsequently rendered gymnocarpous by secondary processes. 


Structure of Crustaceous Lichens.*—J. Steiner has carefully 
studied the structure of the thallus of crustaceous lichens, especially 
in the cases of Verrucaria calciseda and Petractis exanthematica. He 
finds two waysin which the gonidia are formed. The first is an endo- 
genous mode, by division of the entire protoplasm of the hyphal cells, 
after it has surrounded itself with a new membrane. The other is a 
kind of free-cell-formation, several daughter-cells being formed simul- 
taneously in the protoplasm of the mother-cell. The author also 
finds that micro-gonidia (of Minks) are formed in the mother-cell 
by free-cell-formation. He uses chromic acid largely in his 
preparations. 


Coenogonium and the Schwendenerian Theory.j—The genus 
Coenogonium, established in 1820 by Ehrenberg, comprises about 
twenty species which grow in the warm regions of the two hemi- 
spheres. The filamatous elements of the thallus present a great resem- 
blance to the filaments of Conferva, and Dr. Karsten and Professor 
Schwendener recognized in 1862 that around some large conferyoid 
filaments there exist other filaments much more slender, having a 
diameter of about 1-2 », which appear to be hyaline, and which creep 
in some measure on the surface of the large green filaments. There 
is but one single series around the green filaments, and yet this 
series is interrupted, the slender filaments not touching laterally 
in a regular manner, but often showing some anastomosis, and there 
occasionally form, at least in places, a rather close network. Hence 
there are two constituent elements in the thallus of Canogonium as in 
other Lichens, the large green cells still enclosed in their mother-cells, 
corresponding to the gonidia, and the slender hyaline filaments corre- 
sponding to the hyphal filaments. 

It is clear, then, writes Dr. J. Muller, “that according to the 
celebrated theory of Professor Schwendener, announced in 1867, 
the large green filaments will represent the nourishing alga, and the 


* Programme k. k. Staats-Obergymnasiums, Klagenfurt, xxxi. (1881) (2 pls.). 
See Bot. Centralbl., viii. (1881) p. 228. 

+ Arch, Sci. Phys. et Nat., 1881, p. 370. Ann. and Mag. Nat. Hist., viii. 
(1881) pp. 427-9. Grevillea, x. (1882) pp. 87-9. 


390 SUMMARY OF CURRENT RESEARCHES RELATING TO 


slender hyphal filaments will be the parasitic fungus, the two form- 
ing together the thallus of a plant which should no longer, because of 
this union, have its legitimate place amongst the series of the classes 
of plants.” 

In examining a new species, C. pannosum, from Brazil, Dr. Miller 
claims to have discovered “a remarkably demonstrative case,” which 
confirms the general results recently published by Dr. Minks. 

One of the filaments in a great part of its length measured 8 » in 
diameter, and was composed only of a large green tube similar to the 
large green tube of other filaments of the same stratum, and contained 
the cylindrical green gonidia which simulated some articulations of 
Conferva and is the alga of the theory. But at a certain point this 
tube suddenly narrowed and became a very slender capillary tube 
only 2, in diameter, without there being any discontinuation of the 
cavity, the whole forming one single cell, at first large and afterwards 
very narrow, perfectly similar to the slender hyphal tubes of the 
theoretic fungus which enclose the large green tubes or theoretic alga 
in other filaments of the same species. ‘The capillary part, moreover, 
showed clearly the microgonidia in their natural form, size, and 
arrangement. “It follows that one and the same cell would have 
been the theoretical alga on the enlarged gonidia-bearing side and 
the theoretical fungus on the other side which remained narrow and 
contained microgonidia, thus proving in the most absolute manner 
the falsity of the theory, as the same cell cannot at the same time 
belong to two classes of plants. There is neither fungus nor alga; 
the whole is lichen, nothing but lichen ; and the two kinds of tubes. 
so different at the first glance, are only different states of evolution of 
one individual organ. The very slender hyphal tubes are the first part 
containing the microgonidia. This first part may remain always in this 
state, or it may also enlarge and lengthen, while the microgonidia, 
originating by free-cell-formation, may pass into the stage of gonidia, 
and then the narrow hyphal tubes will become large gonidia-bearing 
tubes.” 

Algee. 

Crystalloids of Marine Alge.*—J. Klein states that the 
erystalloids found in marine alge are of two kinds :—(1) Colourless 
or less often brown crystalloids, occurring in the living cells asa 
constituent of their cell-contents, and differing in no essential respect 
from the crystalloids of other plants; and (2) crystalloids of a 
carmine-red colour formed only by the action of certain reagents, as 
sodium chloride, alevhol, or glycerin, on the cell-contents of the 
Floridex, or occasionally formed outside the cells—the rhodospermin 
of Cramer. 

Of the first kind Klein describes the crystalloids found in 20 
species of marine Alge, 5 of them green, the other 15 belonging to 
the Floridee; they differ greatly in form and size, two or three 
modifications sometimes occurring in the same species. They are 
found within the parietal protoplasm, floating in the living cell, in the 

* Pringsheim’s Jahrb. f. wiss. Bot., xiii. (1881), pp. 23-59 (1 pl.). Cf. this 
Journal, iii. (1880) p. 494. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 391 


cell-sap. They are all coloured brown by alcoholic solution of iodine, 
and show the other ordinary reactions of proteinaceous crystalloids. 
They occur most abundantly either in very large-celled Alex like 
Cladophora and Griffithsea, or in those the vegetative thallus of which 
is unicellular, as Acetabularia, Bryopsis, Codium, and Dasycladus ; 
their size and number being apparently dependent on the size of the 
cells in which they occur. They appear to result from the develop- 
ment in the cells of an excess of proteinaceous substances. In some 
instances, as Acetabularia, where they are found only in specimens in 
which there are no spores, they are used up in the formation of the 
spores. 

Rhodospermin has been observed by Cramer and Cohn in Bornetia 
secundiflora, Callithamnion caudatum, C. seminudum, and Ceramium 
rubrum, in which Alge it is formed by the long-continued action of 
the reagents named. What appear to be immature crystalloids of 
rhodospermin have also been detected by Klein in specimens similarly 
treated of Griffithsea phyllamphora and Phlebothamnion versicolor. 


Phyllosiphon Arisari.*—This organism, parasitic on the leaves 
of Arisarum vulgare in Italy, was first observed and described by 
J. Kihn, who regarded it as a Siphonaceous Alga allied to Vaucheria. 
Schmitz has also investigated it, chiefly in reference to its multi- 
nucleated cells, and considers it to be a fungus constituting a special 
group of the Phycomycetes. L. Just has now undertaken a complete 
investigation of its structure and life-history. 

The parasite causes well-defined light-green or yellowish patches 
on the leaves and leaf-stalks of the host, each patch being inhabited 
by a single individual, which attacks the intercellular spaces only. 
Hach individual consists of a single entirely undivided but often 
much-branched interwoven hypha, averaging about 0°05 mm. in 
diameter. 

_The young apices of the branches contain no chlorophyll, but a 
colourless protoplasm rich in larger or smaller granules (microsomes) 
and containing vacuoles and drops of oil. Further from the apices of 
the branches, the hypha is gradually more and more deeply coloured 
by chlorophyll, and containsa larger quantity of oil. When the 
spores are about to be formed, a parietal layer of protoplasm becomes 
nearly homogeneous, and comparatively free from oil-drops, while a 
layer of protoplasm next to this gradually breaks up into numerous 
minute portions, which clothe themselves with cellulose-coats, and 
develope into the spores. The innermost central portion of the 
protoplasm is rich in oil, but contains comparatively few granules 
and no chlorophyll; it absorbs water greedily and swells up. The 
escape of the spores takes place from ten to fourteen days after the first 
appearance of the patches. Just confirms Schmitz’s statement of the 
occurrence of a large number of nuclei in the hyphx ; but he did not, 
like Schmitz, at a subsequent stage find one in each spore ; the spores 
are entirely destitute of nucleus. i 

The spores are of oyal form, averaging about 5 in length and 2-5 


* Bot, Ztg., xl. (1882) pp. 1-8, 17-26, 33-47, 49-57 (1 pl.). 


392 SUMMARY OF CURRENT RESEARCHES RELATING TO 


in diameter; and at the time when they are formed the hyphe are 
found to contain large quantities of starch, which is partly used up 
in the formation of their cellulose-wall, and which is no doubt derived 
from the oil that is present at an earlier stage ; the spores themselves 
do not contain starch. Portions of the hyphe remain colourless, and 
in these no spores are formed. 

Although Phyllosiphon is found only in the intercellular spaces of 
the leaf and leaf-stalk of the host, the protoplasmic contents of the 
neighbouring parenchymatous cells undoubtedly supply it with 
nutriment, and it must be regarded as a true parasite. The inter- 
cellular spaces become in time entirely occupied by it, so that the 
respiration of the host must be greatly impeded. 

As soon as the spores are completely formed in a portion of a 
branch, they escape spontaneously, the expulsion being caused by the 
great capacity for swelling possessed by the central portion of the 
protoplasm, the parietal layer at the same time contracting, and being 
ruptured in consequence. There is always, however, a certain pro- 
portion of the spores left behind in the hypha, surrounded by a portion 
of the protoplasm, and connected with one another by fine bands of 
protoplasm. The portions of the hypha which burst are frequently 
immediately beneath stomata, through which the spores are forced. 
This takes place chiefly on the under side of the leaf, the hyphe 
forcing themselves only rarely and with difficulty between the com- 
paratively closely packed palisade-cells which lie beneath the epi- 
dermis of the upper surface. The expulsion is effected with great 
energy, the spores being forced on to the external surface of the leaf. 
Those which remain in the hyphe continue to grow, some of them 
attaining the size of 8 » diameter and more; while others remain about 
the size of the expelled spores. 

That the green colouring-matter of Phyllosiphon, although not 
occurring in the form of distinct grains, is chlorophyll, is beyond 
doubt ; an alcoholic solution shows all the characteristic spectroscopic 
properties of this substance. It appears certain that this chlorophyll 
is not derived directly from that in the leaf-cells of the host; but 
that it is formed by the organism itself. Its purpose appears to be 
not to decompose carbonic acid in the hyphe, but to pass entirely into 
the spores, which carry on an independent development outside the 
host, and require the chlorophyll for this purpose. 

All attempts at artificial germination of the spores failed, both of 
those that are expelled, and of those, whether larger or smaller, that 
remain in the hyphe ; as also did similar experiments with the hyphe 
themselves. The reason of this failure is no doubt that the spores 
require to go through a period of rest before germinating. In nature 
this period of rest extends from the middle of March, when the 

atches are most abundant (no fresh ones being formed after the 
middle of April) till December, when they begin to appear again. 

Until the complete life-history of Phyllosiphon has been followed 
out, its systematic position must remain in uncertainty. Schmitz’s 
view, that it belongs to the Phycomycetes, must be entirely abandoned ; 
nor does the mode of formation of the spores justify us in placing it, 


ZOOLOGY AND EOTANY, MICROSCOPY, ETC. 393 


with Kiihn, among the Siphonacex. Its parasitic character is the 
only point which gives countenance to the idea that it presents a 
transitional form between Algz and Fungi. All that can be certainly 
stated of this organism is that it is an alga which inhabits the leaves 
and leaf-cells of Arisarum vulgare; and that its spores pass through 
a resting stage outside the host. 


Structure of Corallina.*—Count Solms-Laubach has carried on a 
series of observations, in the zoological station at Naples, on the 
structure of Corallina and its allics. The strong calcification of the 
cell-walls, and the scarcity of the sexual plants, present great difficulties 
in the way of their examination. 

There is no difference in the origin of the tetrasporangia and of 
the conceptacles of the sexual organs in Corallina. The apex of a 
shoot first of all becomes depressed, and then hollowed out with a 
more or less narrow opening. At the bottom of this cavity are found, 
in the tetrasporangia, elongated cells, the transverse division of which 
produces the tetraspores with intermediate paraphyses. The con- 
ceptacles which produce the spermatia bear a close resemblance to the 
spermogonia of fungi. The filaments which bear the spermatia project 
from the opening; at their extremities are from two to four minute 
cells, each of which bears a tuft of very fine sterigma-like threads ; 
and from these sterigmata the spermatia are separated by abstriction. 
When free the spermatium appears as if tailed, from a piece of the 
sterigma still remaining attached to it. 

The procarps are formed from the cells which make up the floor 
of the conceptacle. Their development advances from the centre 
towards the margin ; but while the central trichogyne becomes in the 
meantime prepared for impregnation by a club-like swelling at its 
apex, they become smaller and less frequent towards the margin, and 
the outermost procarps of all have no trichogynes in a receptive 
condition. Notwithstanding this, the production of spores commences 
with the marginal procarps. While in the majority of the Floridex 
each procarp produces a cystocarp, in Corallina only one is formed in 
each conceptacle, resulting from the development of all the procarps. 
After impregnation all the carpogenous cells of the procarp coalesce 
laterally by resorption of the separating walls. The “carpogenous 
fusion-cell” thus formed developes the spores from its entire margin ; 
in C. mediterranea club-shaped cells are produced in great numbers 
from the indented edge, are separated by a wall from the fusion-cell, 
and produce the spores by transverse division. This process exhibits 
a hitherto unknown variety in the mode of producing fruit, resembling 
in some respects that in Dudresnaya. : 

The author draws a comparison between the “ sister-procarps ” of 
Dudresnaya, and the oosphere and synergide or “ sister-archegonia 
of Angiosperms. , 

The treatise concludes with a description of the allied genera 
Amphiroa, Melobesia, Lithophyllum, and Lithothamnion, especially as 


* Graf zu Solms-Laubach, ‘Corallina: eine Monographie,’ 1881 (3 pls.). 
See Bot. Ztg., xxxix. (1881) p, 799. 5 
Ser. 2,—Vou. II. 2D 


394 SUMMARY OF CURRENT RESEARCHES RELATING TO 


regards the mode of formation of the fruit. A new species, Melobesia 
deformans, is described as parasitic on Corallina natalensis, in which, 
instead of the usual regular pinnate structure of the apex of the 
thallus, it branches in all directions into short irregular branches. 
M. callithamnioides produces peculiar gemme, reminding one of those 
of the Sphacelariez. 


Impurities of Drinking Water caused by Vegetable Growth.*— 
W. G. Farlow gives a résumé of what is known respecting the vege- 
table substances which cause impurities in drinking water. The 
most injurious are the blue-green alge the Phycochromacee, but 
only after death. They do not, however, produce infectious diseases ; 
Beggiatoa gives off sulphuretted hydrogen. The following are 
described in detail: — Celospherium Kutzingianum, Clathrocystis 
eruginosa, Anabena flos-aque, and Lyngbya Wollei. 


Fossil Siphonez.|—Meunier-Chalmas has determined the eocene 
genus Ovulites to be identical with Penicillus Link., Nesea Lmx., and 
Ooralliodendron Ktzg., from which he establishes a new section of 
Siphonez, distinguished by their dichotomous branching. One of the 
eocene species is closely allied to the existing Mediterranean Corallio- 
dendron mediterraneum. 'These were previously regarded as con- 
stituting a class of Protozoa, under the name Dactyloporidex, to 
which also belongs Triploporella, found by Steinmann in the calcareous 
beds of the Lebanon. 


Falkenberg’s Algz.{—In his new ‘ Handbook of Alge,’ Falken- 
berg follows in the main de Bary’s classification § ; but introduces the 
doubtful innovation of calling one of his four classes (including 
Melanophycee and Chlorophycee) Algz in a restricted sense. The 
author uses the term “gametes” for any masses of protoplasm, in 
both Thallophytes and Archegoniate, union of which constitutes a 
reproductive act, including therefore oospheres and antherozoids ; the 
result of this union, whether hitherto known as zygospore, oospore, 
or fertilized ovum, he calls a “ zygote.” In the Floridee we have a 
distinct mode of fertilization, viz. the impregnation of a multicellular 
female organ, the “ procarp,” which developes into the fructification 
containing the carpospores. The larger and smaller groups are 
described with great clearness and an admirable selection of the 
salient characters; there is copious reference to the literature of each 
section ; and the illustrations, though not very numerous, are excel- 
lent, many of them being new. Unfortunately there is nothing in 
the shape of an index. 


Motion of Diatoms.||—-Mr. C. M. Vorce, while being unsatisfied 
with any of the theories advanced and having none of his own, 


* Suppl. to First Ann. Rep. of Massachusetts Board of Health, 1880, 
pp. 131-52 (2 pls.). 

+ Bull. Soc. Geol. France, vii. (1881) pp. 661-70. See Bot. Centralbl., viii, 
(1881) p. 270. 

¢ Falkenberg, P.,‘ Die Algen in weitesten Sinne,’ Breslau, 1881 (Encyklo- 
padie der Naturwissenschaften, 1te Abtheil., 23 Lieferung). 

§ See this Journal, i. (1881) p. 273. 

|| Amer. Mon. Micr. Journ., iii. (1882) pp. 43-5, 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 395 


records some of the results of his observations. Many of the pheno- 
mena connected with the motion of diatoms, indicate that the frustules 
are enveloped in a membrane which, if adhesive, would cause many of 
the appearances noted, provided the motion be accounted for. Where 
extraneous matter is seen trailing after a diatom it is, however, as 
likely that the adhesive property resides in it as in the diatom. The 
remarkable alternation of motion seems a very strong objection to the 
ciliary theory and equally so to that of prehensile filaments. No other 
ciliated or flagellate organism exhibits such alternations. Not even 
in the case of large diatoms when moving with great force can any 
trace of cilia or filaments be seen. If ciliary action or currents 
produccd by osmose were the true explanation, we should expect them 
to move adjacent particles when the diatom is held fast, but yet free 
particles are not moved nor is there any evidence of current in the 
water, except where it is in contact with the diatom. In fact, none of 
the suggested causes of motion explain satisfactorily all the phenomena 
observed, and the problem still lies open to some persevering observer. 


MICROSCOPY. 
a, Instruments, Accessories, &c. 


Griffith’s Portable Microscope.*—Mr. E. H. Griffith has further 
modified this instrument, which now “ has the usual coarse adjustment 
by rack and pinion, which is very accurately made, and by an ingenious 
addition, serves also as a fine adjustment. A ring is mounted on the 
axle of the hand-wheel ; a set-screw clamps the hand-wheel when the 
coarse adjustment is effected, so that 
if cannot be moved, and all danger 
of breaking the slide is avoided. Then 
a lever working in the ring moves the 
tubes by means of the same rack and 
pinion. As the lever is itself moved 
by a worm-screw, it forms a very exact 
and delicate focussing arrangement.” 


Parkes’ Class Microscope.—Messrs. 
Parkes have adapted the Microscope 
described ante, vol. i. (1881) p. 655, 
for use as a Class or Demonstrating 
Microscope. It is shown in Fig. 61. 
The handle, in conjunction with the 
base of the stand, enables it to be 
placed on a table in the ordinary way 
when so desired. The condensing lens 
more usually employed when the instrument is being handed round 
a class can be replaced by a mirror. 


Pringsheim’s Photo-chemical Microscope.—Professor Prings- 
heim’s researches on the functions of chlorophyll in the life of the 


* Proc. Amer. Soc. Micr., 1881, p. 85. 


2 pee 


396 SUMMARY -OF CURRENT RESEARCHES RELATING TO 


plant, and the connection of its production and destruction with the 
intensity of the light, have been already fully described,* and we 
now add Dr. A. Tschirch’s description of the special Microscope 
which Professor Pringsheim constructed for observing the effect of 
a high intensity of light on objects directly on the stage, and to 
carry out his method of “ microscopical photo-chemistry ”— a method 
which he considered would also 
be valuable in investigating 
the action of light on proto- 
plasm and the formed consti- 
tuents of the cell-body, for 
investigations on the sensations 
of heat in the lowest animals, 
and in certain cases for ascer- 
taining the truth respecting 
the presence and seat of the 
perception of light. 

The instrument is three 
times larger than the ordinary 
| German] Microscopes, and its 
form resembles that of the 
older Schieck stand. Upon a 
firm tripod a rests the conical 
column b, to which is fixed the 
large round mirror s. The 
latter is 160 mm. in diameter, 
and is as strictly plane as 
possible. It receives the sun- 
light from a heliostat, whose 
mirror must be considerably 
larger than that generally 
used, so that the mirror of 
the Microscope may be fully 
illuminated at any altitude of 
the sun; 235 mm. by 165 mm. 
is a sufficient size. At a dis- 
tance of 165 mm. above the 
mirror, the column supports a 
large stage c, about 110 mm. 
square, beneath which the lens- 
system is screwed for the pro- 
duction of the sun’s image. 
In the instruments hitherto 
employed, a doublet of two 
plano-convex lenses is made use of, placed in the same frame 1, 28 mm. 
from each other. The lower has an aperture of 66 mm. and a focus 
of 93 mm., the aperture of the upper being 48:4 mm. and the focus 
35mm. In this position they form a round image of the sun 0:35 mm. 


* See this Journal, iii, (1880) pp. 117-19, 323-4. 
+ Zeitschr. f. Instrumentenk., i. (1881) pp. 330-3 (4 figs.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 397 


in diameter, and although the lenses are not perfectly achromatic, yet 
it is not too strongly coloured at the margin by chromatic aberration. 

Below the doublet another piece of apparatus can be screwed with 
either two springs, or better a double fork &, for holding the coloured 
solutions or glasses for producing monochromatic images, also the 
media for the absorption of the dark heat-rays. If it be required to 
have additional vessels for the absorption of heat or to employ 
different absorption media at the same time, others can easily be 
fastened under the forks by indiarubber rings, the height of the 
stage c above the mirror giving sufficient space for four or five. It 
is not advisable to fix them above the lenses upon the stage c, because 
while the warmth beneath the lenses extends uniformly through the 
whole of the fluid, there is above them a very hot cone of rays, which 
strongly heats a small portion of the absorption liquid, and with 
liquids such as iodine in bisulphide of carbon explosions may easily 
take place. Indeed, it is in this case necessary, instead of the Desaga 
bottles (at first exclusively employed by Professor Pringsheim), to 
use glass boxes for holding the absorption fluids, of greater width 
than the aperture of the doublet. Jor this purpose round, well- 
polished glass rings can be employed, 10 mm. deep, closed on either 
side by flat glass plates, held together by strong indiarubber rings. 
If these are carefully closed, all aqueous solutions can be kept in 
them for months without evaporating to any considerable extent, par- 
ticularly as a stratum of small crystals speedily forms at the edge, and 
thus makes them still more air-tight. Solutions of bisulphide of 
carbon must often be renewed, because they evaporate, even when 
most tightly closed. 

After many experiments, the following have been proved to be the 
best absorption fluids:—For the absorption of red-yellow, a solution 
of ammonio-oxide of copper; for the blue and red ends of the spectrum, 
solutions of chloride of copper, obtained by the evaporation of a 
saturated solution of the salt, according to the intensity of the colour 
and the extent of the absorption; for the green-violet, a solution of 
bichromate of potassium (K,Cr,O,); and for the orange-violet a 
solution of iodine in bisulphide of carbon or iodine in iodide of 
potassium. As far as can be at present ascertained, solutions of 
organic pigments or of aniline colours are unsuitable, at least they 
possess no superiority over the above solutions. Coloured glass 
plates may be used, if perfectly uniform. Of course, the value of all 
media for absorption must first be tested in the spectroscope. Water 
or a concentrated solution of alum can be used for the absorption of 
the dark heat-rays. 

Above the fixed lower stage is the movable stage 0, moved by the 
screw t!. Itis pierced in the centre, and serves to carry the slide, the 
gas chambers, &c. By means of. the screw, the object can be brought 
into the plane of the sun image formed by the lenses, or immersed in 
it if necessary. The screw t!, as well as t, which moves the micro- 
scope-tube, works on a triangular bar z. ‘The screw ¢ gives the coarse 
focussing, after the object on the stage has been adjusted by means 
of ¢', whilst the micrometer-screw m gives the necessary fine focussing 


398 SUMMARY OF CURRENT RESEARCHES RELATING TO 


movement. The objective is shown at 7. (The author says that it is 
better to produce the fine adjustment by means of a screw on the 
end of the tube, similar to the correction adjustment of objectives.) 

To be able to produce a clear image of the sun, the whole of it 
must be seen, and therefore only low powers can be used. The ficld 
must be about 1 mm. in diameter. To protect the eye against the 
intensity of the light, a number of smoked glasses can be placed on 
the eye-piece 7. 

Two methods were employed by Professor Pringsheim for the 
temperature determinations *: (a) the insertion of a thermo-electric 
couple of iron and nickel into the drop, the results being read off by a 
galvanometer ; and (b) the introduction of small crystals of substances 
of known melting-point. For the latter purpose two substances, azoxy- 
benzol, which melts at 45° C., and mint-camphor, with its melting- 
point 35° C., were found most convenient. 


Waechter’s (or Engell’s) Class or Demonstrating Microscope. 
—This instrument might readily be mistaken for an ordinary brass 
candlestick. Its original form is figured by Harting ¢; Figs. 63 and 
64 show it as im- 
proved by Waechter, 
the lower part being 
seen in Fig. 63 in 
section. 

The body-tube, 
carrying eye - piece 
and objective, slides 
in an outer “sprung” 
tube which is at- 
tached at its lower 
end to a conical base, 
which forms a wide support for the instru- 
ment to stand ujon when not in actual 
use. The inside of the base is polished 
so as to reflect light upon opaque objects. 
The ends of the slides are held beneath a 
metal ring at the lower end of the base, as 
shown in Fig. 64, and they can be removed 
by turning them round till they coincide 
with the two openings in the ring. The in- 
strument is held up to the light and focussed 
by sliding the inner tube in the usual way. 
It can be secured at any given focus if desired by the milled clamp 
ring near the top of the sprung tube. A cover fits over the base 
(shown in Fig. 63) and is pierced with a small hole to act as a dia- 
phragm with high powers. 

The instrument is intended for class demonstration. 

* See translation of Prof. Pringsheim’s Researches by Prof. Bayley Balfour, 
Quart. Journ. Micr. Sci., xxii. (1882) pp. 76-112 (2 pls.). 

+ Harting, P., ‘Das Mikroskop,’ iii. (1866) pp. 196-7 (2 figs.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 399 


Wasserlein’s Saccharometer Microscope.*—This instrument is 
shown in Fig. 65, and its special feature (though one of very doubt- 
ful advantage) is that it enables one and the same instrument to be 
used as an ordinary Microscope and as a saccharometer. 

The following is the method of using it:—The diaphragm having 
been removed from the stage ¢, and the polarizer p substituted, the 
body-tube (with eye-piece and objective) is taken out of the tube r, 
and the saccharometer-tube sr in- 
serted so that its lower end is close Fic. 65. 
over the polarizer. The latter tube 
has at its upper end, and on one 
side, a semicircle sk fixed at right 
angles, on which is a scale gradu- 
ated up to 25° from the centre on 
either side. The analyzer aa is 
inserted, and the mirror s arranged 
in the usual way for microscopical 
observation. The nonius x, at- 
tached to the analyzer, is then 
adjusted by turning the latter so 
that the centre division of the 
nonius exactly agrees with the 0° 
of the scale, and the polarizer is 
revolved on its axis to the right 
or left until the so-called neutral 
point is reached, at which both 
halves of the field of view appear 
of equal intensity and colour. Re- 
moving the analyzer, the glass 
cylinder g (20 cm. long) is inserted 
into the saccharometer-tube (being 
first completely filled with clear 
solution of sugar or urine), and the 
analyzer replaced in its original 
position. On revolving it to the 
right or left until the neutral point 
is again reached, the nonius will ~ 
now have another position on the 
scale, and its central division marks 
the degree, from which the per- 
centage of sugar in the solution can 
be determined. A petroleum lamp 
is the best for the observation. 
The glass cylinder g must be completely filled, so that after being 
closed by the cap k there are no air-bubbles. 

The scale (not divided into 260° but into 180°) shows the quantity 
of glucose or grape-sugar direct. 


* Cf. Hager, H., ‘Das Mikroskop’ (8yo, Berlin, 1879), pp. 45-7, 1 fig. 


400 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Wenham’s Universal Inclining and Rotating Microscope.— 
« Another F.R.M.S.” suggests* that there was one point in connection 
with this Microscope which has been omitted, and claims that the 
merit of the principle of construction is due to Dr. Edmunds, on the 
following grounds :— 

“On November 10, 1880, at the Royal Microscopical Society, 
Dr. W. B. Carpenter exhibited and fully described a small rough 
stand made for students’ purposes by Mr. George Wale, and the record 
of the proceedings of that meeting will be found in the Journal of 
the Society for 1880, p. 1087. From that published record I extract 
the following paragraph :— 

‘Dr. Edmunds pointed out that this most useful microscope-stand 
would be vastly improved if only the are upon which the body turns 
were so constructed that the centre of the circle of which the arc 
forms part were made to coincide in position with the centre of the 
stage. The object would then undergo no movement of translation, 
either in rotating the stage or in turning the optical tube from the 
vertical to the horizontal In rotating the stage, the object would 
turn upon the optic axis; in moving the tube into various degrees 
of obliquity from 0° to 90°, the object would rotate upon its 
horizontal axis. The result would be that, with a thin stage and 
a hemispherical lens in immersion contact with the under surface 
of the slide, all the complicated swinging substages and other 
contrivances now upon the table might be swept away, and every 
angle of illumination could be got by merely inclining the body 
of the Microscope upon its sustaining arc. There would only be 
needed a lamp on a level with the object, with a condenser at its 
focal distance standing upon the table in line between the lamp and 
the object.’ ” 

The writer, in some criticisms of the design, insists that with the 
object centered upon a revolving stage and one movement in altitude, 
all possible illuminations are at command. 

Mr. Wenham subsequently writes t denying that he had previ- 
ously read Dr. Edmunds’ remarks above quoted, and stating that his 
own Microscope was designed before their date. 

A similar disclaimer is made { by Mr. J. M. Moss, the designer of 
the Microscope described in this Journal, i. (1881) p. 516. 


Briicke Lens.—Mr. A. Smith points out, with reference to our 
description of this lens, ante, p. 101, that it is also described in 
Rutherford’s ‘ Outlines of Practical Histology,’ 1876, p. 36, and 
figured, with a holder, on p. 38.§ Our sectional woodcut, Fig. 14, 
was unfortunately reversed by the printer. 


Bausch and Lomb Handy Dissecting Microscope.—This instru- 
ment (Fig. 66) made by the Bausch and Lomb Optical Company, 
for use in mounting Foraminifera or other objects which haye to be 


* Engl. Mech., xxxv. (1882) p. 217. 

+ Ibid., pp. 237 and 282. t Ibid. 

§ It is also referred to by Dr. Carpenter, ‘The Microscope and its Revela- 
tions,’ 1881, pp. 58-9. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 401 


selected from sand and other débris, differs from other similar forms 
in that the base (into which the steel stem supporting the lens is 
screwed) is made of a thick plate of glass, so that by placing a sheet 


Fic. 66. 


GC : 
niin 


of white paper beneath it, and using a bull’s-eye condenser, opaque 
objects can be easily selected for mounting. 


Fic. 67. 


Excelsior Pocket and Dissecting Microscope.—This instrument 
patented by J. J. Bausch (Fig. 67) comes from the United States, 


402 SUMMARY OF CURRENT RESEARCHES RELATING TO 


where it has been several times described. It consists primarily of a 
small wooden case A, about one-third larger than shown in the figure. 
To one end of the lid B is attached one of the ends C of the case, and 
when the lid is reversed it may be slid into the groove of the case, 
and then forms a stand for the lenses and stage. These are supported 
by a steel rod D, the lower end of which is hinged to the lid so that 
it may be turned down and lie in the groove provided for it. When 
raised into the position shown in the figure, it is held securely in 
place by means of the button E, which also serves to retain it in the 
groove when it is turned down. The glass stage G is fitted into a 
frame of hard rubber, and slides easily on the stem D, so as to be 
readily adjustable for focus, while at the same time it may be firmly 
fixed by means of a set-screw, at any desired height, and will then 
serve as a stage for dissecting purposes. The frame which holds the 
lenses F (magnifying 5-30 diameters) fits on the top of the stem. A 
mirror H is fitted into the case, and is readily adjustable by means of 
the button I shown on the outside, so that light may be reflected up 
through the stage when the objects to be examined are transparent. 
When they are to be viewed by reflected light there is a dark plate 
of hard rubber N, which is also carried by the stem D, and may be 
turned under the stage so as to cut off all transmitted light. Dis- 
secting needles (K and I), with handles, fit into appropriate grooves. 
The glass plate is fitted into the stage so as to form a cell capable 
of holding water, so that dissection may be carried on under that 
liquid, or aquatic animals may be kept alive and examined at leisure. 
The stage may also be turned so that the flat side will be uppermost 
if desired. When the lenses and stage are removed they are 
readily packed in the case, and the entire instrument goes into a 
compass “ which readily admits of it being carried in the vest pocket.” 
Dr. Phin recommends * that in order to increase the steadiness of 
the instrument the case should be attached to a board 6 in. x 4 in. x 
2 in. A single small screw is sufficient, and the board can be easily 
detached when it is desired to carry the Microscope in the pocket. 


Hartnack’s Drawing Apparatus (His’s Embryograph).}—Dr. E. 
Hartnack describes his new drawing apparatus, which is a modifica- 
tion of the embryograph of Professor His. He writes:—‘“ It is 
desirable for many purposes of natural history to trace exact out- 
line drawings with low magnifying-powers, and to be able to regulate 
the power so that it may be easy to pass from one scale to another. 
The drawing apparatus hitherto employed in microscopy (even with 
the use of low objectives) have hardly allowed the use of a power 
less than 20; moreover, although through the movement of the tube 
it was not impossible to obtain any scale desired, yet, at any rate, it 
was not convenient. 

“A short time ago Professor W. His published ¢ the design of a 
drawing-apparatus which allowed the power to be varied at will from 
4 to 40. He combined the Oberhiuser camera with a small photo- 

* «How to use the Microscope,’ 4th ed., 1881. 


+ Zeitschr. f. Instrumentenk., i. (1881) pp. 284-7 (1 fig.). 
¢ ‘Anatomie menschlicher Embryonen,’ fol., Leipzig, 1880. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 403 


graphic objective in such a manner, that both could slide backwards 
and forwards in movable sockets, on a bar 60 centimetres long, pro- 
vided with a scale. The bottom of the bar bears the movable 


Fic. 68. 


object-stage, and under this is a microscope mirror. A glass plate 

placed at the side of the apparatus acts as the drawing surface. 
“This apparatus has been employed for years by Professor His, 

but I have endeavoured to give it a more compendious form, and at 


404 SUMMARY OF CURRENT RESEARCHES RELATING TO 


the same time to extend its magnifying power still more. In this I 
have succeeded by employing different objectives for the lower and 
higher powers, so that it was possible to reduce the height of the 
apparatus by a third.” 

The accompanying figure shows the apparatus (Fig. 68), S being 
a circular column, and T an angular bar, the latter divided into 
millimetres. G is the drawing plate placed on the box (88 x 
22:5 x 9°5 cm.) in which the apparatus packs by separating the 
pedestal, column and bar, the stage, &c. 

Professor His writes to Dr. Hartnack as follows as to the use of the 
apparatus :—“ Your form is thoroughly serviceable, and allows of 
correct and convenient working with powers of 4 to 70. According 
to your request I append some information as to its management. 
The regulating of the magnifying power is the first thing to be 
attended to by means of a scale divided into half-millimetres as an 
object. The stage must be placed in its highest position, and the 
objective and the prism moved until the image projected upon the 
glass plate shows the desired magnifying power... . 

“ Hor a power of 4, the stage must be pushed downwards 20 mm., 
and in order to take in the whole of the field of view with powers 
of 4 or 5 it must be unscrewed from its ring and the latter used as 
the stage. 

“The aperture of the stage is only 20 mm.; short or long- 
sighted people should always use the same spectacles. When the 
desired power has been determined the object to be drawn is placed 
on the stage, and focussed only by moving the latter. In order to 
obtain a distinct image, the object must be in the same plane as the 
numbers and strokes of the scale were previously, and if this is 
obtained by unaltered position of the objective and prism, the 
magnifying power of the whole apparatus must remain the same as 
before, the distance of the drawing-surface from the objective remain- 
ing unchanged.” 

[Some general remarks follow as to testing the objectives, the 
regulation of the light, &c. | 

“ Opaque objects are best drawn in liquids. My chief object being 
to draw embryos, I have had unpolished hollow vessels of black glass 
or marble made, 5-20 mm. in depth; the embryos were covered with 
alcohol and a thin glass plate placed over them in such a manner as 
to exclude air bubbles. If it is necessary to keep the embryo in a 
given more or less depressed position, this can be done by using small 
strips of glass suitably bent. 

“The above directions will perhaps suffice to assist the in- 
experienced in the use of the apparatus, and I only hope that others 
may find it, in the elegant and convenient form which you have 
given it, as useful as I have done.” 


Drawing from the Microscope.*—Mr. W. T. Suffolk dispenses 
entirely with the camera lucida, and substitutes a grating ruled in 
squares and placed over the diaphragm of the eye-piece. It is better 


* Sci.-Gossip, 1882, pp. 49-50. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 405 


to have the lines ruled on a double-convex lens of shallow curvature, 
as the interference with the definition is considerably less than 
when a glass with plane surfaces is used: with this arrangement 
Podura-markings can be well shown with a } objective. When the 
binocular is required, a lens without ruling, but of similar curves, 
should be placed in the other eye-piece to equalize the magnifying 
power in each field. A convenient distance for the lines is ;}5 inch, 
this gives a field not too much crowded with squares, and on the 
other hand the divisions are not too large to render the setting out 
of the outline inexact. The drawing is made on ruled paper, the 
squares being of a size suitable to the intended size of the design, 
just as in the well-known draughtsman’s process of enlarging and 
reducing by squares. A drawing of any size, from a small sheet to 
a large lecture diagram, can thus be made directly from the Micro- 
scope. 

"The process also possesses the additional advantage of requiring 
no change in the position of the Microscope, as is the case with the 
camera-lucida, and can be used for a long time without any of 
the strain upon the eye inseparable from the use of instruments, 
where the image and pencil point are viewed through the divided 
pupil of the eye. 

With regard to materials, Mr. Suffolk takes exception to the 
use of flake white for compounding body colours, as in water all 
pigments made of carbonate of lead rapidly become blackened. 
Chinese white, a preparation of oxide of zinc, should alone be used 
for this purpose. He also gives the following list of colours which 
he considers will be found sufficient for nearly every purpose :— 
aureolin,* yellow ochre, lemon yellow, cadmium yellow, ver- 
milion, purple madder, raw sienna, burnt sienna, rose madder, 
light red, brown madder, cobalt, French blue, indigo,j vandyke 
brown, blue black, sepia, viridian.{ In addition to the colours in 
cakes, a few that are likely to be used in large quantities should be 
obtained in tubes; where thick painting is required, this form of 
colour is particularly useful. The Chinese white should be kept 
in a bottle with a greased stopper; in tubes it soon hardens and 
becomes unfit for use; it should be worked with the palette-knife 
and a little water to the consistency required. 

The use of crimson and purple lakes, carmine and all other 
cochineal colours should be avoided; the madders are the only 
safe substitutes. Iodine, scarlet, the chrome yellows, and all aniline 
colours, should find no place in the colour box. 

Very good effects are obtainable by the use of blacklead, and 


* Aureolin, a transparent pure yellow, quite permanent, and an excellent 
substitute for gamboge, as, being without gloss, it can be employed in skies and 
distances. 

+ Indigo is only very slowly acted upon by light, and may he considered 
permanent in the diffused light of an ordinary room; avoid mixing with Indian 
red, which speedily destroys it. 

t A transparent oxide of chromium, perfectly permanent, of great use both 
by itself and in compounding other greens; the opaque oxide of chromium may 
also be found useful; both are extremely permanent colours. 


406 SUMMARY OF CURRENT RESEARCHES RELATING TO 


for rapid work it offers many facilities. In addition to pencils of 
the usual kind, some with broad leads will be found useful for 
covering larger surfaces. Very delicate tints can be made with 
blacklead powder rubbed on the paper with a suitable leather stump. 
Tints of any depth can also be obtained from blacklead used as a 
water-colour, which can be procured in cakes. 

Blacklead, charcoal, and chalk drawings can be permanently fixed, 
by saturating the paper from behind with a varnish composed of 
bleached shellac and alcohol. This should be very freely applied 
and dried in a warm room or with caution before a fire. The strength 
should be such that it will just dry without leaving a gloss on the 
paper. Winsor and Newton’s white lac varnish, mixed with an 
equal bulk of methylated spirit, will be the right strength. After 
this treatment a pencil drawing may be placed in the portfolio, and 
even exposed to some amount of rubbing, without injury. The var- 
nish does no harm to any water-colour tints that may be used in 
combination with pencil. 


Ulmer’s Silk Thread Movement.*—J. Ulmer suggests the use 
of a silk thread for microscope-tubes and the eye-pieces of telescopes. 
The tube T (Figs. 69-72) has above and below in the socket two 
guides ¢¢, against which it is gently pressed by the small pulley d and 
spring e, by which means easy sliding is secured. The movement of 


Fic. 69. Fic. 70. 


the tube is effected by the silk thread f which is attached toa spring g 
and screw h, both of which are fixed to the tube. The spring is slit as 
shown in the figures, and the screw is hollow and serves for stretching 
the thread and the spring, after the former has been laid in the slit, 
and turned round the pinion , which is fluted to avoid slipping. The 
rotation of the tube is prevented by making the support by which the 
female screw at h is attached to the tube slide in a slit in H. 

The apparatus works, it is said, without any “‘loss of time,” and 
secures an easy motion, at the same time being very simple. 


* Centralztg. f. Optik u. Med., ii. (1881) p. 148 (4 figs.), 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 407 


Diaphragms for Limiting the Apertures of Objectives—Mr. 
J. B. Dancer proposes * other forms of diaphragms for this purpose, 
the iris-diaphragm being unsuitable on account of the “ragged” 
outline which it gives. The first form is an oblong plate of 
diaphragms, which slides in an adapter screwed to the nose-piece, the 
second is a circular rotating plate. 

The third method utilizes the ordinary double nose-piece. A 
shallow recess is made in the top edge of one of the female screw 
parts of the nose-piece to receive thin metallic (numbered): disks, 
having holes of suitable diameters. A disk with the required aperture 
can be dropped into the recess by merely moving the arm, which 
carries the objective, on one side. A wire hook is useful for lifting 
them out again. 

A still later device is shown in Fig. 73, and is a combination 
of the first and third plans. An oblong 
plate slides in an adapter, but instead 
of being pierced with several apertures 
of different sizes, it has two apertures 
of equal size, into which can be dropped 
the various diaphragm disks used with 
the third plan. This gives great facility 
for removing and changing the dia- 
phragms quickly, and might, we think, be usefully adapted for taking 
the diaphragms required for the diffraction experiments. 

It must be observed, however, that the object for which the use of 
these diaphragms was suggested is not practically attainable. The 
suggestion was founded on the fact that a low-angled objective has 
greater penetrating power than a high-angled one, and it was considered 
that by using a diaphragm at the back of the objective, thus cutting 
down the aperture, an objective of wide aperture could be made to do 
duty as a narrow-angled one also; so that two classes of objectives were 
unnecessary. As Professor Abbe points out at p. 308, the plan adopted 
in the construction of wide-angled objectives will not allow of such 
a double use; and it is still necessary to employ two classes of ob- 
jectives, using those of small aperture when penetration is required. 


Correction-adjustment for Homogeneous-immersion Objectives. 
—Dr. G. E. Blackham discusses the reasons suggested for dispensing 
with an adjustment to these objectives, viz. no risk of decentering, 
the existence of a one best position in all objectives, the cost of the 
adjustment, and the trouble of correcting. 

To these objections the following he considers to be conclusive 
replies. 

First, if the brass-work is done with a degree of skill at all com- 
mensurate with that necessarily expended on the glass-work of a 
really first-class homogeneous-immersion objective, there need be no 
fear of injurious decentering by the movements of the adjustment- 
collar. 

Second, while it is true that the adjustment by means of varying 


* North. Microscopist, ii. (1882) pp. 89-90, 92. 
+ Proc, Amer. Soc. Micr., 1881, pp. 61-4. 


408 SUMMARY OF CURRENT RESEARCHES RELATING TO 


position of the systems is only an expedient, yet if it can be shown 
that it reaches the desired end more certainly, speedily, and accurately 
than any other, the objection to it must fall to the ground. 

Third, that while it is conceded that really first-class metal-work 
is expensive, if it can be shown that it is necessary, the objections to 
it must also fall, 

The term homogeneous-immersion, though honestly applied and 
correct as to the idea, is only approximately true at present, as no 
truly homogeneous-immersion fluid has as yet been discovered, so far 
as the author can learn. That is, no fluid whose optical properties 
are absolutely identical with those of the front lens of any objective. 
The refractive power of crown glass has been closely approximated, 
but minute differences of dispersive power remain; and even if this 
difficulty could be overcome, the varying refractive and dispersive 
powers of various samples of crown-glass must always remain an 
unknown quantity in our problem, to be provided for by some kind of 
adjustment. 

This fact has been recognized by at least one maker, who advises 
to correct for extremely thick or thin covers, by means of the draw- 
tube, and furnishes two fluids, one for use with direct central light, 
and the other with very oblique light. Of course it follows that for 
perfect accuracy of correction by means of the immersion fluid, a 
different fluid would be needed for each degree of obliquity of illu- 
mination. That this would involve serious inconvenience hardly 
needs demonstration; more especially when we consider that it is 
often desirable to examine an object under gradually varying obliquity 
of illumination, from direct central to the most oblique the lens can 
utilize. 

Another point is the variation in the human eye; which must be 
compensated for in some way. 

“Tt appears then, that the homogeneous-immersion system does 
not entirely obviate the necessity for adjustments of some kind, though 
it greatly lessens their extent. That these small residual adjustments 
can be made with more ease, rapidity, and accuracy by means of the 
screw-collar moving the back system of the objective, than by means 
of varying the distance between the objective and eye-piece by means 
of the draw-tube, or by varying the refractive and dispersive powers 
of the immersion medium by means of mixtures of various oils, &c., 
in varying proportions will, I think, on consideration be generally 
admitted. 

But this greater ease, rapidity, and accuracy of adjustment with 
homogeneous-immersion (so called), is not the only argument in 
favour of the retention of the adjustable mounting for objectives. 
Most immersion fluids are apt to vary in their optical properties with 
their age or the state of the weather. One of the best of them, the 
solution of the sulpho-carbolate of zine in glycerine, has its refractive 
power increased in very dry and decreased in very wet weather. In 
this case it is more convenient to turn the adjustment-collar slightly, 
than to make a new solution for immersion. 

Again, it is often desirable to use an objective with a much longer 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 409 


or shorter tube than it was specially constructed for, or to use some 
other immersion medium than its own, water or glycerine for instance, 
for some special purpose. Here, again, the advantage, nay, the 
necessity, of the adjustable mounting, becomes evident. I believe 
then that I have shown :— 

First, that homogeneous immersion has not been and is not likely 
to be more than approximately attained. 

Second, that even if it should be fully attained, so far as the front 
lens of the objective is concerned, the varying refractive and disper- 
sive powers of different eyes, and different samples of cover-glass 
would always remain to be accounted for. 

Third, hence adjustment of some kind will always be necessary. 

Fourth, that a well-made adjustable mounting for the objective is 
the most convenient, satisfactory, and perfect arrangement for this 
purpose yet devised. 

Fifth, that by means of such an adjustable mounting the range of 
usefulness of an objective, as well as the convenience of using it are 
greatly increased, and therefore,— 

Sixth, homogeneous-immersion objectives (so called or real), as 
well as all other objectives of wide angle, should be made adjustable.” 


Hitchcock’s Modified Form of Vertical Illuminator.*—Professor 
R. Hitchcock suggests another form for a vertical illuminator, which, 
he thinks, will be better than the ordinary one, and more convenient 
for use. 

“ Instead of the reflector now used, a small glass reflecting prism is 
placed in the nose-piece in the same way and in the same position as 
the Wenham binocular prism, and in the case of binocular Micro- 
scopes should replace the latter. The back surface of the prism, 
which receives the light, may be either plane or curved; it might be 
found advisable to make this surface act as a lens to throw the light 
upon the back of the objective in the most advantageous manner for 
illumination. All parts of the prism not used should be blackened, 
so that no light except what passes down to the objective can enter 
the tube. A rotating diaphragm can be added, working in front of 
the exposed surface of the prism; but this would probably be an 
unnecessary expense.” f 


Flesch’s Finder.{—Dr. Max Flesch describes the arrangement 
shown in Fig. 74, as a simple contrivance for finding objects on a 
slide where a more complicated apparatus is not suitable. 

A clip of horse-shoe shape attached by two pins, holds the slide 
upon the stage. The outer sides of both arms are bevelled off and all 
four sides graduated. When a particular object or part of an object 
is in the field a line is drawn with a pencil along both sides of each 
arm crossing the slide. The numbers of the divisions are also marked 
on the slide with short cross lines, as shown in Fig. 75. If the slide 
is again brought into its original position, as determined by the 

* Amer. Mon. Micr. Journ., iii. (1882) p. 54. 

+ Mr. J. W. Stephenson informs us that he had a vertical illuminator on this 


plan constructed in 1879. 
; Arch. f. Mikr. Anat., xx. (1882) pp. 502-3 (2 figs.). 


Ser. 2.—Vot. II. Oars 


410 SUMMARY OF CURRENT RESEARCHES RELATING TO 


coincidence of the arms and divisions of the clip with the lines on 
the slide, the object will necessarily be in the field of view. The 


Fic. 74. 


arrangement has been found sufficient for an Hipparchia scale, with a 
power of 150. 

Burnett's Rotating Live-Box.—This is thus described by Mr. 
R. T. Burnett, its designer:—* The arrangement of this live-box 
is very simple. Hitherto live-boxes have had the outer cases, 
which hold the strong or bottom glass, screwed into, or fixed 
firmly to, the plate that goes upon the stage. This one is constructed 
so that the outer case fits into a flange or cylinder its own depth. 
The cylinder is made fast to the plate, leaving the outer case, 
together with the inner case, free to be rotated at the will of the 
manipulator, forming, in point of fact, an ordinary live-box resting 
within a deeply flanged plate. 

In using the ordinary live-box, it has hitherto been necessary to 
take it off the stage whenever the observer has been desirous of 
turning the object round, or when, in the absence of an ‘ erector,’ it 
has been necessary to have an object which has been placed head 
downwards changed to an upright position. This is avoided by the 
rotating live-box. 

Further, in using the ordinary live-box with high objectives, the 
latter will project within the rim of the live-box ; consequently no such 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 411 


change could be made without altering the focus of the Microscope, 
and causing a loss of time in readjusting the focus and in finding the 
particular part of the object. By the rotating live-box no alteration 
of the focus is necessary.” 

Schklarewski’s Hot-water Stage.*—This is represented in Fig. 
76. The water, heated by gas or a spirit lamp, passes from the 
vessel C, through the tube a, into the hollow stage O placed on the 
microscope-stand A. A thermometer T shows the temperature. The 


water, after passing through the stage and becoming cool, flows back 
again through b into the vessel C, whilst that which is more heated 
flows through c, and the indiarubber tube attached to it, into another 
receptacle. The stage does not appear to differ essentially from other 
well-known forms. | 


Abbe’s Condenser.—This apparatus as originally devised ¢ was 
not easily applicable to any stand but that of Zeiss for which it was 
specially made. It has now been so modified (Figs. 77 and 7 8) that 
it can be applied to the usual substage fitting. 

The upper lens A is a thick plano-convex, somewhat larger than 
a hemisphere. Just below it is a large bi-convex lens serving as a 
collecting lens to A. The upper focus of the combination is about 
2 mm. (in glass) above the plane face of A, that is, about the distance 
of an object on an ordinary slide. A small metal cap with a central 
pin-hole can be placed over A for convenience of centering. B is a 
box-fitting for diaphragms, &c., forming part of the carrier-plate C, 


* Thanhoffer's ‘Das Mikroskop und seine Anwendung,’ 1880, pp. 88-9 
(1 fig.). 

t Mon. Micr. Journ., xiii. (1875) pp. 77-82 (1 fig.). 5 5 

E 


412 SUMMARY OF CURRENT RESEARCHES RELATING TO 


made to rotate immediately below and in the axis of the optical 
combination. The carrier-plate moves laterally by rackwork acted 
upon by the toothed pinion D. To facilitate changing the diaphragms 
C can be swung out of the axis on the swivel-joint E, as shown in 


Fic. 77. Fic. 78. 


Fig. 78. Cireular, lune-shaped, and other diaphragms are supplied, 
which give a large variety of effects of obliquity both in altitude and 
in azimuth when used with the lateral and rotating movements of C. 
For black-ground illumination a central stop is placed in B, and 
Zeiss supplies special diaphragms to be applied at the back of several 
of his objectives of large aperture which ensure the dark-ground 
when used in conjunction with this condenser. With objectives of 
greater aperture than 1:0 N.A. the condenser must of course be in 
immersion contact with the base of the slide. The condenser has a 
numerical aperture of 1:4 nearly. 


Bausch and Lomb’s Immersion Illuminator.—This illuminator 
(of which we have no drawing) is intended “to utilize the full 
capacity of medium and wide angle objectives,’ up to 152° in crown 
glass or 1:47 N.A. Its mounting is arranged with an internal 
diaphragm, which is placed directly under the posterior system of 
lenses, and entirely contained in the tube comprising the mounting, 
so as to avoid the projection existing with other condensers, and 
allows the light to enter only from below. By revolving the milled 
ring of the mounting, the diaphragm is made to pass laterally from 
the centre to the extreme edge of the illuminator, thereby projecting 
a bundle of rays of any obliquity, between 0° (central illumination) 
and the extreme possible limit 1-47 N.A. When the diaphragm is 
at its extreme, a second slit, at right angles to it, giving the same 
volume of light, is opened by the further movement of the milled 
ring. The makers add that “the fact that it is used with only central 
illumination of the mirror, will prove especially valuable to those 
who do not possess instruments with the modern swinging substage 
and mirror bar.” 


Bausch’s Paraboloid.*—Mr. E. Bausch describes a new form of 
paraboloid in which the hemispherical hollow in the top is left clear, 


* Proc. Amer. Soc. Micr. 1881, p. 88. 


EE 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 413 


there being a blackened brass cup to fit into it when desired. A hemi- 
spherical glass lens fits in the same hollow, “ optical contact” being 
made between the paraboloid and the lens by glycerine and a homo- 
geneous medium. There is also an opening in the side for the 
admission of light, all other light being stopped out. 

The apparatus can thus be used as a Wenham reflex illuminator 
or an ordinary paraboloid, at the same time providing a hemispherical 
lens if required. 


Browning’s Simple Heliostat—Fig. 79 shows a simple form of 
heliostat for the Microscope. It is provided with three movements: 
—(1) The rotation in the vertical plane of the inner cylindrical 
fitting, carrying the mirror arm, on the fixed toothed disk, by the 
large milled head; (2) The in- 
clination of the mirror in the 
double gimbal fitting by means of 
the endless screw (milled head to 
the right) acting upon a counter- 
sunk worm on the posterior sector 
forming the inner are of the 
gimbal; (3) The rotation of the 
entire gimbal-mounting of the 
mirror by the milled head beneath 
(this movement serving princi- 
pally for the first adjustment of 
the mirror to the direction in 
the horizontal plane in which the 
reflected beam is to be utilized). 

The particular heliostat figured 
was adapted for mounting in the 
substage of a Microscope which in 
that case would have to be inclined 
so that the optic axis is parallel 
with the pole of the earth. The 
mirror being then adjusted to the direction required, the beam of 
reflected light would be maintained on the same spot by the simple 
rotation of the mirror arm on the toothed disk, acting as the hour 
circle of an equatorially mounted telescope, the inner gimbal are 
acting as the declination circle. 

It can also (and probably better), be mounted vertically upon a 
separate stand apart from the Microscope, or in a shutter exposed to 
a southern aspect. 


Hayem and Nachet’s Modified Hematometer—This is now 
arranged as shown in Figs. 80-82, and is thus described by M. 
Nachet :— 

“The hematometer, formed of a cell with a flat base, devised by 
Dr. G. Hayem and myself some years ago, has been adopted by the 
different authors who have experimented on the number of the blood- 
corpuscles. Some modifications have been made in the apparatus, 
without changing it essentially, amongst which may be noted the 


414 SUMMARY OF CURRENT RESEARCHES RELATING TO 


attempt to do away with the eye-piece micrometer ruled in squares. 
Drs. Thomas and Gowers suggested engraving the lines on the base of 
the cell itself, an eye-piece micrometer being replaced by an objective 
micrometer. It is, however, in the first place, nearly impossible to 


Fig. 80. 


engrave lines as fine as are required on such smooth and polished 
glass as that of which the cell is made, so as to be clearly visible ; 
there is also the risk of breakage, &c., and the inconvenience that 
when the cell is filled with the liquid, the lines are still fainter and 
unsuitable for being easily seen. 

The new arrangement consists of a metal plate OC, to which a 


Kier sl 


tube B, about 20 mm. long, is screwed, containing on its upper part a 
system of lenses, intended to form a very small image of a set of 
divisions P in squares, engraved or photographed on glass, and placed 
at the lower end of the tube. The tube is introduced into the opening 
of the stage, and on the plate C C is placed the cell of the hemato- 
meter, containing the liquid with the globules in suspension. These 
soon fall to the bottom plate of the cell, and the focus of the lenses 
being exactly upon this plate at O, the image of the squares P is 
formed there and is visible through the Microscope, at the same time 
as that of the globules (see Fig. 82). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 415 


By this means all the inconveniences attendant upon engraving 
the divisions at the bottom of the cell are avoided. The divisions 
may be as exact and as strongly marked as possible, the image 


Fie. 82. 


io} 


ro) 


(e) 
[e} 
2) 
fe) 
(eo) 
fe) 
ai 


ie) 


depending entirely upon the intensity of the photograph and its size 
on the reciprocal distance of P and O.” 


Fasoldt’s Test-plate.*— Professor R. Hitchcock does not consider 
that the diffraction spectra alleged to have been seen by Mr. Fasoldt are 
any proof of the presence of the separate lines claimed, and “ would 
like Mr. Fasoldt to inform us how fine the individual lines of his 
wonderful plate are? If the plate has 1,000,000 lines to the inch, 
the individual lines cannot be broader than half a millionth of an 
inch. Can such fine lines be ruled? Then it is a question in 
mechanics, whether a tool can be made so steady that it can draw a 
line without a tremor of half a millionth of an inch—for if not, then 
the lines of the plate must run together. 

“In regard to the first question, there is already some evidence 
that Mr. Fasoldt’s assumption is not justified. Professor W. A. 
Rogers ruled a plate with his machine set for 500,000 lines to the 
inch, making every fifth and tenth line longer than the rest. He 
then measured the long lines, where they projected from the band, 
and found that they were so broad, that they overlapped each other, 
leaving no spaces between them. Evidently, therefore, the band of 
500,000 lines did not consist of distinct lines. The spectra were, 
nevertheless, clear and bright. Hence, we are forced to conclude 
that the spectra do not prove that Mr. Fasoldt’s plate contains 
1,000,000 lines to the inch.” 

We have not seen Mr. Fasoldt’s claim as to the diffraction spectra 


* Amer. Mon. Micr, Journ., iii. (1882) pp. 52-3. 


416 SUMMARY OF CURRENT RESEARCHES RELATING TO 


and do not know how it is worded, but however worded any such 
claim must originate in a very strange misconception. 
The number of lines to an inch capable of being resolved are 
defined by the equation 
A 
nsin u 


5=3 


Taking for simplicity at 5555 inch (instead of +5269 y), and 
u to be 180° (sin uw being = 1), it will be seen that for 6 to give 
1,000,000 lines to an inch, n—the refractive index of the immersion 
medium (and with it the objective and the test-plate)—must be made 
of a substance whose refractive index is 10. What is this wonderful 
substance—the philosopher’s stone of the microscopist ? 

Or to put the same point in another way :— 

The diffraction spectra of lines 145,000 to the inch, can only just 
be got into the back lens of a homogeneous-immersion objective of 
1-50 N.A. To get in the diffraction spectra of 1,000,000 to the inch, 
the aperture must have been not less than 10 N.A.! How has this 
aperture been obtained at a time too when we are congratulating 
ourselves on having reached 1°47 N.A.? 

The visibility of the diffraction spectra, so far from proving the 
existence of lines at the rate of 1,000,000 to an inch, is conclusive 
proof that they do not exist, and that nothing beyond 150,000 at any 
rate could have been observed. 


High Resolving-power.— We have been referred to what is 
termed a claim of Dr. T.S. Up de Graff to have resolved lines as fine 
as 152,400 to the inch. Dr. De Graff's statement is, however, simply 
that he has resolved the last band of Fasoldt’s 19-band plate, and be 
is eareful to add “152,400 to an inch, the number of lines claimed 
by the maker to be ruled in this band” (italics in original). While, 
therefore, fully accepting the observer’s statement that the lines 
which he did resolve were true and not spurious lines, we have, of 
course, to wait for the demonstration that the maker’s claim is correct 
before commencing again, with clean boards, to endeavour to esta- 
blish a theory of resolution! The theoretical resolving power of the 
largest apertured lens yet made (Powell and Lealand’s 1°47 N.A.) is 
about 141,500 lines to an inch. 


Binocular Microscopes.*—Professor R. Hitchcock, in discussing 
the question whether there is any real advantage in binocular over 
monocular instruments, thinks that the problem is a very difficult one 
if we attempt to decide on theoretical grounds what effect any par- 
ticular binocular arrangement will have when applied to the examin- 
ation of a specified object ; to explain how much of the appearance of 
relief is real, and how much is merely a mental impression produced 
by the two images in the two eyes. 

He, therefore, prefers to confine the discussion to the practical 
side of the subject. “If the question is whether there is any advan- 
tage in a binocular Microscope in studying the form of objects— 


* Amer. Mon. Micr. Journ., iii. (1882) pp. 45-8 (8 figs.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 417 


whether the appearance of relief that it gives is necessary to enable us 
to form a correct idea of the true shape of objects in which the appear- 
ance of relief is most striking—the answer must be a decided negative. 
It is true that the binocular does reveal more of the form of an object 
at the first glance than the monocular ; but it isa matter of experience 
that those who use only one eye in microscopical work, never make 
the mistake of supposing that an object is flat merely because it seems 
to be so. A very short experience enables one to form a perfectly 
correct idea of the shape of any object by a few turns of the focussing 
screw. Hence, persons whose means are limited, and who desire to 
invest a small sum of money in a Microscope to be used for purposes 
of study, would do well to forego any thought of purchasing binocular 
stands. 

“On the other hand, there are certain qualities of binoculars which 
commend them to all workers who can afford the additional cost. 
Apart from any stereoscopic effects it is doubtless true that the use 
of two eyes whenever possible renders continued observation less 
tiresome than when only one can be applied to the tube. Some 
writers have stated that with a monocular one eye is overstrained 
while the other is not used at all, contending that by using the 
binocular that trouble is overcome. The two eyes should be used 
alternately with the monocular, hence they ought to become trained 
for sharpness of vision, but we doubt if the binocular aids in the way 
assumed, for we are inclined to believe that although both eyes are 
simultaneously employed with the binocular, the right eye does most 
of the real work, the left eye only supplementing its fellow and giving 
the binocular effect. However this may be, there is a certain ease in 
working with binoculars which doubtless makes the strain upon the 
eyes less than with monoculars. 

“The stereoscopic effects, while not of great practical importance 
as already stated, certainly render many objects more attractive to 
look at. For this reason a Microscope for the entertainment and 
instruction of friends should certainly be a binocular.” 

Mr. G. E. Fell also discusses the binocular Microscope and stereo- 
scopic vision,* and the objections that have been made to such instru- 
ments, at the same time describing the Powell and Lealand, Nachet, 
Wenham, Tolles, H. L. Smith, Abbe, and Barnard forms. He is 
inclined to believe that a trifling temporary defect in the faculty of 
consentaneous focalization may be produced by the continued use of 
one eye with the monocular, so that the microscopist may be really 
incapacitated for realizing the advantage or effect of stereoscopic 
vision with the binocular, but he does not agree that the convergence 
of the tubes produces an unnatural straining of the lateral recti 
muscles, as the angle of that convergence is about equal to that of the 
eyes in ordinary observation at 10 to 12 inches. 

Professor Hamilton L. Smith} prefers the Nachet binocular, though 
he considers that the Wenham binocular “is beautifully simple in 
theory and, except for one thing, perfect in practice. The one great 


* Proc. Amer. Soc. Micr., 1881, pp. 69-83 (8 figs.). 
+ Ibid., pp. 89-91. 


418 SUMMARY OF CURRENT RESEARCHES RELATING TO 


fault is it necessitates a very quick convergence of the optical axis. 
. . . With young eyes and nominally sound this difficulty is not 
distressing, but for older eyes it becomes annoying. Always upon 
looking up after using Wenham’s binocular, fora while he had found 
an unpleasant feeling of readjustment of the eyes to the normal con- 
dition.” He also thinks that “a trained eye would make out about 
as well and with less trouble the actual structure of any object under 
examination with the monocular as with the binocular—at least such 
was his own experience offered with much diffiidence. For his own 
special work with high power and wide angles they are not really 
suited, but others engaged in another line of investigation requiring 
only medium power and low angles may find them serviceable.” 


Electric Light in Microscopy.*—Dr. H. Van Heurck describes 
his experiments with the electric light, commencing by pointing out 
that, notwithstanding the perfection of homogeneous-immersion 
objectives, which show readily delicate details, it frequently happens 
that the study of diatoms (particularly the small forms) gives con- 
siderable trouble, as well by the difficulty of resolving the strie as 
by the impossibility of counting them with a low power. It is 
necessary, therefore, to have recourse to a high power, or even to 
monochromatic light, which is not always possible, as the sun is fre- 
quently hidden, particularly in winter. He has, therefore, for some 
time thought of the electric light for illumination with the Microscope, 
and his experiments have demonstrated that the incandescent electric 
light supplies the illumination par excellence which the microscopist 


uires. 

The author then proceeds to treat of the production of the elec- 
tricity, referring to the fact that in a probably near future the 
inhabitants of large towns will have electricity distributed at their 
doors, so that the necessities to be met will be principally those of 
microscopists who live in the country or in small centres. Two 
modes are at present open for the production of electricity, dynamo- 
electric machines and batteries. The former are, however, out of the 
question for the purpose under consideration, a small battery being 
capable of supplying all that is required at a small expense and little 
trouble. 

As to the different forms of batteries the Bunsen is the most 
powerful, but the vapours which it gives off, and other points, render 
it unsuitable for microscopical purposes. In his original paper the 
author recommended the Tommasi battery, a modification of the 
former, as in every way preferable and cheaper, giving at the same 
time a full and detailed description of it, with woodcuts. He has 
since written us, however, that the battery of E. Regnier is still 
better and the Tommasi has been discarded. The former is thus 
described in a supplementary note :— 

The Regnier battery has modified Daniell elements with very 
large surface. They consist of a narrow rectangular cell in copper 
(45 x 23 x 5} em.) within which is a zinc plate, closely enveloped 


* Bull. Soc. Belg. Micr., vii. (1882) pp. lxii.-Lxxiii. (3 figs.). 


a 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 419 


in a diaphragm of vegetable parchment, and then sewn up in a linen 
cloth. The cell is filled with pure water, and 400 grammes of 
sulphate of copper placed in the upper part. Thus charged, the 
battery will act during 24 hours, and these may be taken either 
all together or at different times, the battery losing nothing of its 
charge when it is not employed. When the battery is discharged 
(which may be known by the liquid becoming colourless) a third of 
the liquid is removed by an indiarubber tube and replaced by pure 
water and a new charge of sulphate of copper as before. 

The author then treats of the storage of the electricity, and 
gives a woodcut of an “accumulator” made by EH. Regnier on the 
Planté-Faure system. It consists essentially of two plates of lead, 
coated with a thick layer of minium, separated, wrapped in flannel, 
rolled upon themselves, and placed in a glass cylinder, well closed, 
and containing water acidulated with 10 per cent. of sulphuric 
acid. On leaving off work in the evening a series of these accumu- 
lators can be connected with the battery and left until the following 
evening, and a sufficient amount of electricity will have been stored 
up for further use. 

The third point dealt with is lamps. The arc light is inadmissible, 
and only the incandescent lamps can properly be used. Those not in 
_@ vacuum are very good for photo-micrography, but are too brilliant 
for ordinary work. Of incandescent lamps in a vacuum or rarefied 
medium (Swan, Edison, and Maxim) the author prefers those of Swan, 
which can be worked with a force much less than the Maxim lamps. 
He obtained from Newcastle some special lamps, eminently suitable 
for microscopical researches, and now employs those exclusively. 
They are nearly spherical, and are about 3 cm. in diameter, giving a 
brilliant light with very little expenditure of force. For obtaining 
a beautiful white light 5-7 Tommasi elements or 3 or 4 accumulators 
are sufficient. The 4 accumulators will feed the little lamp for more 
than 12 hours, and a permanent light could therefore be obtained by 
putting the battery in operation once or twice a week. 

The above details refer, as will be seen, to the Tommasi battery. 
In the note as to the new battery the author only says “ for the little 
microscope Swan lamps, 5 Regnier elements and an accumulator 
must be employed.” 

The advantages to be obtained from the employment of the electric 
light by the microscopist are of two kinds, which the author classifies 
under the head of “Illumination of the Microscope” and “ Photo- 
micrography.” As to the first, he says that “The incandescent 
electric light surpasses all other illumination. It has the softness of 
a good petroleum lamp, and shows delicate details nearly as well as 
monochromatic light. The delicate striz of Amphipleura and the 
19th band of Nobert’s test are seen with perfect sharpness. Professor 
Abbe, to whom we communicated the result of our researches, attri- 
butes it to two causes, lst, the much greater whiteness of the light ; 
consequently it contains more blue and violet rays. But, as it has 
been demonstrated by the measurements made by the Professor with 
different monochromatic lights, that the resolving-power of an 


420 SUMMARY OF CURRENT RESEARCHES RELATING TO 


objective of given aperture increases in the same ratio as the wave- 
length of the light employed diminishes, it follows that the electric 
light ought to show delicate details more easily than the yellow light 
of gas or lamps. 2nd. The specific intensity of the electric light 
being much more considerable than that of other artificial lights, 
sufficient illumination is obtained with a pencil much narrower than 
that which must be employed to obtain the same luminous intensity 
with gas or diffused daylight. Rays much more oblique can there- 
fore be used.” 

The lamp should be placed in a small box, the cover of which is 
pierced with an opening. The Microscope is placed on the box, the 
mirror being turned away from the axis or entirely removed. The 
light of the lamp is then concentrated by a plano-conyex lens and 
directed into the condenser. 

The use of the electric light also allows the microscopist at any 
moment to photograph an object in the field, and directions are given 
for proceeding on the dry plate method. 


Definition of’ Natural and Artificial Objects.**—In some “ Re- 
collections of my Life,” T. Baumann says that the difference between 
a natural and an artificial object cannot be more briefly or more 
precisely defined than by saying that under the Microscope the natural 
object is always more beautiful and the artificial one always more 
imperfect the more the magnifying power is increased. 


Cole’s ‘‘ Studies in Microscopical Science.”—Mr. A. C. Cole has 
projected a weekly periodical under this title “for the use of students, 
professors and teachers, the medical profession, and others interested 
in the progress of the natural sciences or engaged in higher educa- 
tion . . . tomeet a want, which, even in these days of practical teaching, 
is felt by every student commencing the study of the natural sciences 
equally with those who are desirous of devoting their leisure to 
scientific pursuits. 

“It is proposed by means of a carefully prepared and typical 
object for the Microscope, together with a drawing and descriptive 
essay, to supply students, microscopists, and members of the medical 
profession, with a ready means for studying, 1. Microscopical biology 
in all its branches, 2. The physiological and pathological histology 
of the body. 3. The essentially modern sciences of microscopical 
paleontology, mineralogy, and petrology. 

“ Subscribers will be entitled to receive every week: 1. A micro- 
scopical preparation of the highest class and most perfect finish. 
2. A printed description of the preparation, in which will be noted: 
a. The literature concerning it. b. The habitat, &c. c. The methods 
employed in its preparation as a means of study. d. Its principal 
features, and any necessary additional remarks. 3. A lithographed 
or engraved drawing, or diagram, of the preparation, in the execution 
of which the following details will be most carefully considered and 
adhered to. a. Accuracy. 0. Finish. cc. Indication of Natural 
Size, &e. 

“The preparations during the first year will consist of a series 


* Zeitschr, f. Instrumentenk., ii. (1882) pp. 46-51. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 421 


of 26 histological, 18 botanical, and 8 petrological sections issued 
alternately, and from time to time special subjects will be illustrated 
by a complete series of preparations with their accompanying draw- 
ings and descriptions. 

«“ Announcements will be made for the benefit of special students 
and practical instruction by this means afforded to those desirous of 
studying such works as — 

Elementary Biology.. Hualey and Martin, Parker, é&c. 

Practical Histology .. Klein, Ranvier, Rutherford, Schifer, &c. 
Practical Botany .. De Bary, Prantl, Sachs, Thomé, Vines, éc. 
Practical Zoology .. Claus, Gegenbaur, Hualey, Parker, éc. 
Practical Geology .. Geikie, Rosenbusch, Rutley, Zirkel, &c. 

“Tt is intended that each series when complete shall form a most 
thoroughly practical work upon the subjects illustrated. 

“The letterpress accompanying each series of preparations will 
afford demonstrations in the special department illustrated, and will 
thus assist students very materially in their work for university 
honours, degrees, &c. The drawings and letterpress will be uniform 
in size, a preface and index will be added, and a suitable case sup- 
plied at the end of each year in which the separate numbers can be 
bound. Small cabinets to contain the preparations, numbered and 
arranged in such a manner that any object may be readily found on 
referring to the letterpress (and vice versd) will also be supplied.” 

The first number, which is before us, deals with yellow fibro- 
cartilage. After a full description of the specimen, which is a 
longitudinal vertical section of the pinna of the ear of the cow 
stained with logwood and eosin, the action of reagents is described. 
The various methods of preparation which can be adopted for stain- 
ing and mounting are detailed very fully and completely, and will 
be found of great practical value. A Bibliography is added in 
which 37 books and articles are noted. An excellent coloured plate 
shows the appearance of a section X 333. The second part deals in 
a similar way with a section of copper beech, stained carmine and 
iodine green. The plate shows the section « 25. 

Mr. Cole’s idea appears to us to be an excellent one in every 
respect, and there is no doubt as to his capability of carrying it 
out as announced, especially as regards the practical branches of the 
subject, in which he has acquired a very wide reputation. It only 
remains for those (and they ought not to be few) who are interested 
in the success of the scheme to ‘support it. 


Journal of the Postal Microscopical Society.—The first number 
of this quarterly journal has just been issued (56 pp. 9 figs. and 
5 plates), containing a considerable amount of useful matter, as will 
be seen from the following list of contents :—History of the Society ; 
Numerical Aperture; Microscopical examination of Chlorophyll, 
Inulin, and Protein-crystals; Tubifex rivulorum ; Diatoms; How to 
prepare Foraminifera; Lichens. There are notes by Mr. Tuffen 
West on the slides that have passed through his hands whilst Presi- 
dent, and a selection of notes from the Society’s note-books, with 
short notes on preparation and mounting, reviews, apparatus, reports 
of the Bath Microscopical Society, and Correspondence. If the future 


422 SUMMARY OF CURRENT RESEARCHES RELATING TO 


numbers of the journal are equal to the first it will be a very useful 
one, and should be supported by all the members of the Society. 


Aperture Diaphragm, [Ante, p. 262.] 
Journ. Post. Micr. Soc., I. (1882) p. 51 (2 figs.). 
Aytwarv’s (H. P.) Working Microscope. 
North. Microscopist, II. (1882) pp. 90-1. 
Baumann, T.—Erinnerungen aus meinem Leben, ein Beitrag zur Geschichte 
der Pracisionsmechanik. (Recollections from My Life, a Contribution to the 
History of Precision-mechanics.) 
[Includes definition of natural and artificial objects, supra, p. 420. 
Zeitschr. f. Instrumentenk., II. (1882) pp. 46-51. 
Bavuscu & Loms Co.’s New Trichinoscope. [Ante, p. 258.] 
Amer, Natural., XVI. (1882) pp. 429-31 (2 figs.). 
Bavscn’s Homogeneous-Immersion Objectives. 
[+ to ~—140° crown-glass angle—adjustable for water or glycerine 
arieeetond Amer. Natural., XVI. (1882) pp. 347. 
Buackuam, G. E.—Remarks on New Immersion Objectives. 
[‘* Do not be troubled or deterred from efforts by ‘theoretical limits,’ no 
matter how high the authority that sets them. Newton’s dictum as to 
the impossibility of constructing an achromatic telescope was a 
stumbling-block in the progress of optical construction and astro- 
nomical observation for years, and Mr. Wenham’s count of 82° balsam 
(1:00 N.A.), had it not been disregarded, would have proved an equal 
barrier in the path of microscopical progress.” ] 
Bausch § Lomb Optical Co.’s Supplement to Catalogue, Feb. 1882, p. 7. 
Bouton, T.—Parkes’ Class Microscope. [Supra, p. 395.] 
Journ, Post. Micr, Soc., I. (1882) pp. 52, 55 (2 figs.). 
C., F.—Microscopical Club. 
[Reply to H. C.S. as to the formation of such a club.] 
Engl. Mech., XXX V. (1882) p. 80. 
Cox, J. D.—Telescopic Field and Microscopic Aperture. 
Amer. Mon. Micr. Journ., III. (1882) pp. 61-9 (3 figs.) p. 76. 
Crisp, F.—Notes sur l’ouverture, la vision microscopique et la valeur des 
objectifs & immersion a grand angle (Notes on Aperture, Microscopical Vision, 
and the value of wide-angled Immersion Objectives)—contd: 
(Transl. of paper I. (1881) pp. 303-60.] 
Journ. de Microgr., VI. (1882) pp. 143-5, 190-3. 
CrovuLLesors, M.—Théorie élémentaire des Lentilles épaisses. (Elementary 
Theory of Thick Lenses.) 
[Geometrical explanation of Gauss’s theory—Compound Microscope, pp. 
82-3.] x. & 117 pp. (50 figs.). 8vo, Paris, 1882. 
D., E. T.—On Drawing and Painting from the Microscope. 
[Neutral tint reflector has often been a snare and delusion to young 
draughtsmen on account of the reversal of the image, which renders it 
difficult to fill in the drawing from the Microscope afterwards—prefers 


the Wollaston. ] Sci.-Gossip, 1882, p, 74. 
- », The Microscope and Fine Art. 
{General remarks on Microscopical drawing and painting. ] 
Sci.-Gossip, 1882, pp. 97-8. 
Dancer, J. B.—On a Method of Mounting the Limiting Apertures for In- 
creasing the Penetrating Power of Objectives. (Supra, p. 407.] 
North. Microscopist, II. (1882) p. 92. 
Davis, G. E.—The Aperture Shutter. 
[Further remarks as to the origin of the suggestion. ] 
North. Microscopist, II. (1882) pp. 88-90 (2 figs.) p. 128, 
Ss “~ Electric Light for Microscopy. 
[Notes as to a trial of the Swan lamp in 1881.] 
North. Microscopist, II, (1882) p. 129. 
Desy, J.—Apparatus for obtaining monochromatic light. 
[The beam of light from the lamp is condensed by a large bull’s-eye, 
passed through a slit, and refracted by a bisulphide of carbon prism. ] 


a 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 423 


Ditrmar, W.—Mikroskopische Ablesevorrichtung fiir feine Waagen. (Micro- 
scopical reading apparatus for fine balances.) 

{Recommends a Microscope for reading off the scale. ] 

Zeitschr. f. Instrumentenk., IL. (1882) pp. 63-4. 
“ English Mechanic ” Microscopical Society. 

[Suggestions for working the proposed Society. ] 

Engl. Mech., XX XV. (1882) p. 195. 
Ermencem, HE. van.—The Vertical Illuminator. 
[Transl]. of paper in ‘ Bull. Soc. Belg. Micr.,’ ante, p. 266.] 
Amer. Mon. Micr. Journ., IIL. (1882) pp. 48-9. 
Fiescu, M.—Hinfache Vorrichtung zum Wiederauffinden wichtiger Stellen 
in Mikroskopischen Praparaten. (Simple contrivance for finding again important 
points in microscopical preparations.) [Supra, p. 409. ] 
Arch. f. Mikr. Anat., XX. (1882) pp. 502-3 (1 fig.). 
a » Ueber einige Verbesserungen an Seibert und Krafft’s Mikroskop- 
Stativ. (On some improvements in Seibert and Krafft’s microscope-stand.) 

[The tube, instead of sliding in a socket, moves by a pinion on a brass 
plate, the edges of which slide in grooves attached to the tube (similar 
in short to the usual English plan). ‘This allows the tube to be more 
securely fixed and to be raised higher from the stage when low powers 
are required. The analyzer and polarizer can also be more readily 
placed in any given relative position. The tube is blackened inside. ] 

Arch, f. Mikr. Anat., XX. (1882) pp. 504-5, 
Harpy, J. D.—On an improved Compressorium. 
Journ. Quek. Micr. Club, I. (1882) pp. 35-6, 51-2 (2 figs.). 
Hevrcx, H. van.—La lumiere électrique appliquee aux recherches de la 
micrographie. (The electric light applied to microscopical researches.) 
[Supra, p. 418.] 
Bull. Soc. Belg. Micr., VII. (1882) pp. 1xii.-Ixxiii. (3 figs.). 
Sep. repr. also with additional note on the new Regnier Battery. 
Hircucocs, R.—Binocular Microscopes. [Supra, p. 416.] 
Amer, Mon. Micr. Journ., III. (1882) pp. 45-8 (8 figs.). 
$5 i About Stands. 

[Reply to query of the Editors of the ‘ Botanical Gazette, (“. .. Is it a 
fact that the extra appliances, &c., are more things of ‘fuss and feather’ 
than fruitful additions to biological laboratories? ”) That some ac- 
cessories are certainly important, but there is a long list of them which 
embraces many that are quite useless, and very many others that are 
mere conveniences. Some few are almost indispensable, and Microscopes 
should be purchased with substages in every case. ] 

Amer. Mon, Micr, Journ., III. (1882) p. 54. 

+) p A New Form of Vertical Illuminator. (Supra, p. 409.] 

Amer, Mon. Micr. Journ., IIL. (1882) pp. 54, 78. 
is Pe “The Microscope.” 

[Further remarks as to Prof. Stowell’s Journal. ] 

Amer. Mon. Micr. Journ., III. (1882) p. 58. 
» ns The Microscope in Medicine. 
[Complaint of the want of interest in practical Microscopy among 


iy siete Amer. Mon. Micr. Journ., III. (1882) pp. 75-6. 
ro = Ruled Lines as Tests. 

[‘* Resolving power alone is not a test to be depended on.” 

Amer. Mon. Micr. Journ., III. (1882) pp. 77-8. 
Hotmers, E.—What is the meaning of x ? 

[Reply to T. R. J. infra who “is confusing himself needlessly.” “If a 
drawing of a man 5 feet high be made 20 feet he is x 4 whether the 
grain of his skin becomes visible or not.” ] 

; Sci.-Gossip, 1882, p. 114. 
J., T. R.— What is the meaning of the sign x ? 

[Points out the error in describing a drawing as x 500 when it is drawn 
from an object x 50, and the drawing enlarged 10 times—‘* unless there 
be detail corresponding with the amplitude the object is not x so 


aman alse. Sci.-Gossip, 1882, p. 89. 


424 SUMMARY OF CURRENT RESEARCHES RELATING TO 


Kain, —.— Drawing Microscopie Objects. 

[‘* Mr. Kain showed (at a meeting of the Camden Society) a method of 
throwing the image downward by means of a convex mirror, and 
receiving the magnified image upon a sheet of white paper placed upon 
the table. It could then be traced without difficulty.’”] 

Amer. Mon. Micr, Journ., 111. (1882) p. 59. 
Kary, C, H.—Photo-micrography. 
Amer. Mon. Micr. Journ., III. (1882) pp. 71-2, 75. 

Lossner, O. W.—Telemikroskop (Telemicroscope). 

[Abstract of German patent for a combination of a Microscope and a 

Telescope, D. R. P. 16672, 5th Apr. 1881.] 
Zeitschr. f. Instrumentenk., IL. (1882) p. 156. 
Martens, A.—Instrumentenstativ mit Kugelgelenken und Kiemmringen. 
(Microscope-stand with ball joints and fastening rings.) 

Zeitschr. f. Instrumentenk., I1. (1882) p. 112 (1 fig.). 

Matruirssen, L.—Die mittleren Brechungsindices fester und fliissiger K6rper 

im Vergleich mit ihrer Totaldispersion. (The mean refractive indices of solid 
and fluid substances in comparison with their total dispersions.) 

Centr.-Ztg. f. Opt. u. Med., II1. (1882) pp. 73-4. 

Microscope and Magic-lantern. 

[Remarks as to the best objectives by “ Sunlight.) 

Engl. Mech., XX XY. (1882) p. 202. 
Morrison, —.—Drawing Microscopie Objects. 

[‘* Mr. Morrison showed (at a meeting of the Camden Society) an arrange- 
ment on the plan of a camera-obscura by which the image was thrown 
upwards upon a piece of transparent paper placed upon a plate of 
plain glass.” | Amer. Mon. Micr. Journ., III. (1882) p. 59. 

Mounting Micro. Lenses. 

[Directions by “ Prismatique,” W. J. Lancaster, and “ Micro.”’ 

Engl, Mech., XX XV. (1882) pp. 180, 199, 227. 
Objectives and Eye-pieces, best method of determining focal length of. 
[Suggestion that Prof. Abbe should give a “short exposition of the 


subject,” with diagrams by Akakia. ] Engl. Mech., XX XV. (1882) p. 227. 
Objectives, Verification Department for. 
(Tabular results of measurements of objectives (contd.). ] 
North. Microscopist, II. (1882) pp. 87, 107, 128-9. 
OLLarD, J. A.— Microscopical Drawings. 
[Recommends as a simple camera lucida “ Forrest’s Reflector,”—a thin 
glass cover adjusted to the eye-piece.] Sci.-Gossip, 1882, p. 90. 
PINKERNELLE, W.—Apparat zur Erleichterung der mikroskop. Untersuchung 
von Fliissigkeiten. (Apparatus for facilitating the microscopical investigation of 
fiuids.) German Patent, No, 18071, 31st May, 1881. 
Postal Microscopical Society, History of. 
Journ. Post. Mier. Soc., I. (1882) pp. 4-7. 
President’s Address (contd.). Engl. Mech., XXXY. (1882) pp. 213-5. 
Scuréper, H.—Ueber Projections-Mikroskope. (On projection Microscopes.) 
(Abstr. of original article, ante, p. 274.] 
Zeitschr. f. Instrumentenk., II. (1882) p. 71 (1 fig.). 
VEREKER, J. G. P.— Numerical Aperture. 
Journ. Post. Micr. Soc., I. (1882) pp. 7-12 (5 figs.). 
WENHAM’s Universal Inclining and Rotating Microscope. 
This Journal, 11. (1882) pp. 255-7 (4 figs. and 1 pl.). 
Engl. Mech., XX XY. (1882) pp. 143-5 (5 figs.), 
North. Microscopist, 11. (1852) pp. 108-10 (1 pl.). 
[Remarks by F.R.M.S., supplementing the previous description, and 
dealing with (1) general design, (2) fine adjustment, (3) stage, (4) 
diaphragms and substage centering motions. ] 
Engl. Mech., XXXV. (1882) p. 195. 
[Claim by “ Another F.R.M.S.” that it is the invention of Dr. kdmunds, 
and replies by F. H. Wenham, Ross and Co., and J. M. Moss; and 
further remarks by “ Another F.R.MLS.,” “ Yet Another F.R.MS.,” 
and ‘‘ Akakia.” Supra, p. 400.) : 
Engl. Mech., XX XY. (1882) pp. 217, 237, 260, and 261. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 425 


B. Collecting, Mounting and Examining Objects, &c. 


Colouring Living Microscopical Organisms.*—A. Certes points 
out that distilled and ordinary fresh water are toxic to marine In- 
fusoria, and a great number of species which live in water of very 
different density and chemical composition. 

In these special cases the colouring of living Infusoria will not 
succeed, or only very imperfectly, unless care is taken to use a 
solution of the colouring material prepared with the water which it 
is desired to examine. 

The difficulties attendant upon the above procedure may be 
avoided by the following process, which has also the advantage that 
no foreign organisms are introduced. Place on the slide a drop of 
the alcoholic solution (1:1000) of the reagent, cyanine, BBBBB 
violet, gentian violet, dahlia, Bismarck brown, &c. Spread out the 
liquid with a glass rod and let it evaporate. When the evaporation is 
complete, or nearly complete, add a drop of the water (fresh or salt) 
intended to be studied and put on the cover-glass. Almost imme- 
diately, if the dose has been well calculatel, the phenomena of 
paralysis and of colouring of the Infusoria may be observed. 

In this way the author has coloured several species of Vorticelle, 
Paramecia, Ameebee, Polytoma wvella (flagellate) and Bacteria. 


Mounting Histological Preparations with Carbolic Acid and 
Balsam.j—Mr. G. E. Fell transfers the prepared sections from the 
alcoholic preservative fluid to a clean slip and pours strong carbolic acid 
over the object immediately, allowing it to run off at one corner of the 
slide into a suitable receptacle. A thin cover-glass previously prepared 
with Canada balsam is then quickly applied, the balsam replacing the 
carbolic acid which, owing to its short contact with the tissue of the 
preparation, does not produce in it any appreciable shrinkage while 
still acting as a clearing agent. Pouring the alcohol over the pre- 
paration on the slide (followed by the carbolic acid) and allowing 
it to run off again, removes the extraneous filaments, bits of dust, &c., 
from about the specimen. 

Dr. R. G. Mohr { considers, however, that it is scarcely worth 
while to experiment with carbolic acid for histological mounts, as 
Seiler’s method of mounting in alcohol balsam is so simple and 
perfect as to leave nothing more to be desired. 


Differentiating Motor and Sensory Nerves.s—By the method 
adopted by L. Léwe and entitled “‘ Method for obtaining preparations 
which demonstrate the structural difference between motor and sensory 
nerves, and are hence adapted for enabling the course of the fibres 
of the peripheral system of nerves to be traced,” a fcetal rabbit, 
3 to 4 centimetres in length, taken from the mother during life, 

* Sep. repr. Bull. Soc. Zool. France, vi. (1881). See the author’s previous 
papers, ante, pp. 279 and 280. 

+ Proc. Amer. Soc. Micr., 1881, p 87, 

t Ibid., p. 88. 

§ Zool. Anzeiger, iii. (1880) p. 503. 

Ser. 2.—Vor, II. 2F 


426 SUMMARY OF CURRENT RESEARCHES RELATING TO 


is placed for three months in not less than one litre of saturated 
solution of bichromate of potash, and the liquid changed twice; the 
bichromate is then carefully washed out with water, and the speci- 
men finally stained entire in one litre of a weakly ammoniacal 
solution of carminate of ammonia, and may then be prepared for 
cutting sections by imbedding in gum-glycerine in the usual way. 
The motor nerves are darkly stained, and the sensory nerves 
faintly so. 


Preparing Nerve-fibrils of the Brain.* —For making preparations 
to show the nerve-fibrils of the brain, J. Stilling calls renewed atten- 
tion to Von Recklinghausen’s method of macerating well-hardened 
specimens in wood-vinegar. 


Cochineal Carmine-solution.t—J. Czokor grinds to a fine powder 
7 grammes of cochineal (the same amount whatever quality is used) 
with as much burnt alum, and mixes it with 700 grammes distilled 
water and boils it down to 400 grammes. After cooling, a trace of 
carbolic acid solution is added and the whole filtered. From time to 
time a little carbolic acid solution must be added, and the solution 
filtered again. It stains substances prepared with alcohol or with 
chromic acid, the latter rather more slowly than the former. A 
solution made with a better quality of cochineal stains the nuclei 
the same colour as hematoxylin, the other tissues in various shades 
of red; if it is prepared with “ Blut”-cochineal the intermediate tissue 
is less deeply coloured, the action resembling that of Grenacher’s 
carmine. 


Polarized Light as an Addition to Staining.j—Mr. A. D. Michael, 
describing a plan of which he and Dr. J. Matthews are joint authors, 
suggests that polarized light might be of use as an addition to staining 
for vegetable and some animal substances, as it seemed to differentiate 
tissues somewhat in the same way. In practice it might be found to 
have its disadvantages, but it might have its advantages. No special 
preparation of the tissues was required, and the conditions were more 
natural than if they had undergone the process of bleaching and 
staining. It would also be possible, when they had a known selenite, 
always to repeat the same effect when required, whereas stained 
tissues frequently fade, and if there were any doubt as to the meaning 
of what was seen, the effects could be altered, and results secured that 
would be unattainable with the fixed effects of double staining. There 
was, of course, no difficulty in getting triple staining, or producing 
various colours, but the object which he showed was as if stained 
with a single colour only. [It was a section of Serjanus shown 
with oblique polarized light ona black ground.| He had heard some 
discussion as to the best means of obtaining polarized light on a 
black ground, and had heard it suggested that the results depended 
entirely on the object, that it was to be obtained only now and then 


* Arch. Mikr. Anat., xviii. (1880) p. 468. 

+ Arch. Mikr. Anat., xviii. (1880) pp. 412-14. Cf. Zool. Jahresber. Neapel for 
1880, i. p. 42. 

3} Journ. Quek. Micr. Club, i. (1882) pp. 49-51. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 427 


in the case of certain objects which had a capacity for it, also that 
it depended on the size of the polarizing prism and other causes. 
No doubt these did affect it to some extent, but he was of opinion 
that the effect was largely a question of what the object was mounted 
in. He did not find that Canada balsam was the best medium ; in 
fact, the best effects were obtained by mounting in glycerine, when 
there was very little difficulty in making out the details, and the 
object looked brighter upon a blacker ground as contrasted with its 
appearance when mounted in balsam. He thought the idea would be 
found worth attention, especially where it was desirable to examine 
objects under various conditions of direct and oblique light. 

Mr. T. C. White, in the discussion which followed, said that he 
had always found a good deal of difficulty in using polarized light on 
objects mounted in glycerine; while Dr. Matthews, on the point of 
the superiority of glycerine over balsam for the kind of examination 
in question, described his experience as rather the reverse of 
Mr. Michael’s. Whether this arose from any difference in the objects 
he could not say, but he thought the effect was probably due to some 
difference in their density ; the only way of settling the point would 
be to mount the same objects in both ways. He also thought that 
with extremely oblique light, they got fringes of colour—probably 
owing to diffraction. Mr. Michael had been very successful in getting 
dark-ground illumination, but there appeared to be some curious 
effect produced by a spot lens, less colour being produced in that way 
than without, although it might be supposed that the contrary would 
be the case. As to the differentiation of tissues, precisely the same 
effects were obtained as by staining, but with the advantage that a 
harmonious appearance was always produced, whereas with staining 
the selective power caused differences of colour which were not 
always harmonious. 


Wickersheimer’s Preservative Liquid.*—To the wet and dry 
methods of preserving with this liquid G. Brisike adds a third, the 
“damp” method. The subject is injected with the liquid, and the 
separate parts are moistened with it during dissection, and then en- 
closed in an air-tight vessel. The method is suited to nerves, tendons, 
fasciz, vessels, and ligaments; muscles become bleached under its action. 
It appears to have no real advantages over a proper treatment with spirit, 
and the fact of the liquid containing poison must be borne in mind. 

Brésike takes this occasion to correct an important printer’s error 
in the official patent.t Instead of 10 grammes of arsenious acid it 
should be 20 grammes. 

Preparing Hemoglobin Crystals.{—By using pyrogallic acid, 
C. Wedl has prepared for studying with the Microscope, spectro- 
scope, and polariscope, hemoglobin crystals from the blood of man, 
other mammals, and frogs. The best plan is to remove the colouring 


* Centralbl. f. med. Wiss., ii. (1880) pp. 17-19. Cf. Jahresber. Anat. Physiol., 
ix. (1880) p. 82. 

t See this Journal, iii. (1880) pp. 325-6. 

{ Virchow’s Archiv, Ixxx. (1880) p. 172. Cf. Zool. Jahresber. Neapel for 


1880, i. p. 57, 
2 Reg 


428 SUMMARY OF CURRENT RESEARCHES RELATING TO 


matter from the corpuscles by the action of water, and to place 
some of the solution of hemoglobin thus obtained, under a cover- 
glass (which should be raised at one side by a slip of glass laid 
beneath it) adding some pyrogallic acid. Frog’s blood, the colouring 
matter of which is very difficult to extract, must remain in a moist 
chamber for several days before the acid is applied; the crystals then 
appear within the corpuscles. (Kélliker has seen them similarly in 
the red corpuscles of Perea fluviatilis.) It usually requires several 
hours’ treatment to produce the crystals; they will keep for some time 
in the fluid. 


Preserving Flowers.*—For preserving the colours of parts of 
flowers which it is desired to mount for the Microscope, Mr. G. Stocker 
finds a saturated solution of the ordinary potash alum crystallized 
(Al, 8S0,, K, SO,, 24 H,O) most excellent. The objects should 
remain in the liquid for ten minutes or so, and then be dried between 
bibulous paper, placed in turpentine to render them transparent, and 
mounted in balsam. A portion of the vexillum of Ulea Europceus so 
mounted is without any of that reddishness which accompanies speci- 
mens mounted in the ordinary way ; and a stigma of Crocus sativus is 
as full of colour as in its original state. 


Cleaning Diatoms.{—Mr. K. M. Cunningham makes the following 
suggestion for cleaning diatomaceous material when largely con- 
taminated with sand. “A quantity of the material is placed in a 
teaspoon, and water is then added until the teaspoon is nearly filled ; 
the spoon is gently shaken with a back and forth or a circular motion, 
for a few seconds or longer, when the water must be quickly drawn 
off by applying the tip of a finger to the point of the spoon, taking 
care to draw off the superficial water, without allowing the heavier 
sediment to pass over the point. Pour from the spoon into a watch- 
glass, the surplus water is then drained off, and the diatoms removed 
for mounting. This method produces a magical concentration of the 
diatoms, large and small, making the remaining sand inconspicuous 
by the superabundance of the diatoms.” 


Gaule’s Method of Imbedding.{—The following method of im- 
bedding was worked out by Dr. J. Gaule, by whom it was com- 
municated to Professor E. A. Birge, who, having tried it on all sorts 
of tissue, can fully recommend it. 

« A piece of tissue of convenient size is to be taken, treated with 
the ordinary reagents, and stained in the mass. If large it may be 
convenient to remove it from the staining fluid to alcohol for a few 
hours and then replace it. Wheu thoroughly stained, the specimen 
is to be put in 70 per cent. alcohol for about twelve hours, then 
transferred to absolute alcohol until it is completely dehydrated. 
Then put it in oil of cloves overnight, or leave it there until it is 
convenient to imbed it. Place it in turpentine half an hour—large 


* Sci.-Gossip, 1882, pp. 65-6. 
+ Amer. Mon. Micr. Journ., iii. (1882) p. 14. 
t Ibid., pp. 73-5. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 429 


specimens for a longer time—then transfer it to a mixture of tur- 
pentine and paraffin, kept melted on a water-bath at about 40°C. In 
this the specimen, if from liver or intestine, &c., should remain for an 
hour or more; small nerves and blood-vessels of course need not 
remain so long. Then transfer it to a bath of pure paraffin, melted 
at a temperature of 60° C., and leave it for the same length of time. 
Indeed, if care be taken that the temperature does not materially 
exceed 60°, the specimen may remain as long as convenient. When 
the tissue is thoroughly saturated with melted paraffin, a small 
paper box may be filled with melted paraffin and the specimen 
placed in it to cool. If properly imbedded, a cut surface has a 
smooth and shining appearance. No line of division must appear 
between the specimen and surrounding paraffin. The whole mass 
should cut, as nearly as possible, ike one homogeneous mass of 
paraffin. 

The subsequent handling of the sections varies with their nature. 
Moderately thick sections of firm tissue may be placed in turpentine 
to remove the paraffin and mounted as usual in chloroform-balsam. 
Thin specimens, or those which come to pieces when the parafiin 
is removed, like thin sections of liver, &c., may be laid on the slide 
on which they are to be mounted, and the paraffin washed out by 
benzine, carefully applied by a dropping-tube ; allow the benzine to 
evaporate, then lay on the cover-glass and apply thin chloroform- 
balsam at the edge of the cover. For exceedingly delicate specimens, 
such as embryos or osmic acid nerves, another method may be used. 
Lay the section on the slide, wet with absolute alcohol, and let the 
alcohol completely evaporate, leaving the specimen attached to the 
slide; carefully heat until the paraffin is softened or slightly 
melted. When cool, let a few drops of benzine—best applied with a 
brush—run over the section until most of the paraffin is gone. 
When dry, apply the cover-glass and put a thin solution of Canada- 
balsam in xylol to its edge. The xylol may be used instead of 
benzine, but it is more expensive. 

This method is very convenient, especially for histological 
laboratories. The specimen once imbedded can be kept for years, 
and new sections cut as wanted. No change takes place in it, nor 
can it dry up. It is suited to all tissues. I have imbedded all 
vertebrate soft tissues, chick and trout embryos, hydras, snails, 
angle worms, clams, star-fishes, &c., with equal success in every 
case. The ease with which the sections can be made fully com- 
pensates for the time required to imbed. The merest tyro, provided 
with a good section-cutter, a brush to keep the sections from rolling, 
and such a specimen, must be a bungler indeed if he cannot cut at 
least thirty even sections from each millimetre of a moderate-sized 
specimen such as the cesophagus of a rabbit. With a little practice 
he should be able to cut a millimetre into one hundred sections without 
losing more than two. The writer has cut a frog’s spinal cord so 
imbedded into 926 sections = mm. thick in one day, and mounted 
them without losing any sections. No one who practises with 
these specimens will regard this as much of a feat; it is simply a 


> 


430 SUMMARY OF CURRENT RESEARCHES RELATING TO 


hard day’s work. Specimens as large as the central hemisphere of 
a rabbit can be stained and imbedded whole. 

I append my notes on the spinal cord of a frog, showing the 
times used in the various processes :— 

Cord put into 3 per cent. nitric acid, 2 hours. 

Seventy per cent. alcohol, 6 hours. 

Stained in hematoxylin, 4 hours. 

Seventy per cent. alcohol, overnight. 

Ninety-five per cent. alcohol, 24 hours. 

Oil of cloves, 24 hours (did not wish to imbed till next day) ; 
then, 

Turpentine, stir half-an-hour. 

Turpentine and paraffin, 1 hour. 

Paraffin, 1 hour. 

It should be remembered that these cords imbed easily. 

One caution further; select paraffin, if possible, which is bluish- 
transparent, and which rings slightly when struck. The white 
opaque sort is by no means as good. Any addition of paraffin-oil, 
turpentine, &c., to soften the paraffin, renders it granular and brittle, 
and is decidedly injurious to its cutting qualities.” 


Williams’ Freezing Microtome adapted for Use with Ether.*— 
The original form of this Microtome was described and figured at 
pp. 697-9 of vol. i. (1881). It subsequently occurred to Mr. J. W. 


Groves that it would be an improvement if it were adapted for the use 
of ether as a freezing agent instead of ice and salt. Mr. J. Swift 


* Journ. Quek. Micr. Club, vi. (1881) pp. 293-5 (2 figs.). 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 431 


accordingly worked out the details of the adaptation which is shown 
in Fig. 83. D represents the wooden bowl of the original form 
altered to hold the ether freezing apparatus. A and B are the razor 
frame and bowl-cover with the glass-plate top upon which the former 
is moved. The central brass cylinder, instead of being solid, is 
hollow, so that the ether spray may play up the inside and impinge 
upon the lower surface of the brass-plate I, upon the upper surface of 
which the material to be frozenis placed. In the figure, the hollowed 
cylinder is seen to open below into the ether-containing chamber, 
into the lower part of which also opens a horizontal tube, which turns 
up at right angles and ends in a funnel-shaped extremity G, over 
which screws a cap. 

In the centre of the bottom of this chamber is a circular aperture 
closed by a piece of brass tubing, which passes up vertically to end 
in a cone with a very small aperture, and having another small hole 
in it towards the bottom. The lower end of this tube is plugged, and 
through the plug E passes vertically a very fine tube, which is con- 
tinuous below with the tube from the apparatus for pumping in 
air. ‘This consists of an indiarubber pump F, connected by a short 
piece of tubing with a slightly distensible ball covered with 
netting, and from the opposite side of which a piece of indiarubber 
tubing passes on towards E. Inthe side of the large hollow cylinder 
of the machine is inserted a small tube connected with a length of 
pipe H for the escape of the spray after use. 

The method of freezing is as follows:—After the material has 
been partially hardened, and the hardening agent removed, place it 
on the brass plate I with a little gum mucilage;* then unscrew the 
cap G, fill the chamber with ether, replace the cap, and commence 
pumping by pressing the ball F vigorously and rapidly in the palm 
of the hand. Air will thus be pumped into the net-covered ball, from 
which it will issue in a continuous jet along the indiarubber tube, 
up the small tube, through the plug H, and again through the hole at 
the apex of the conical-ended vertical tube, to pass straight up against 
the under surface of the plate I. The rush of air thus produced 
causes pressure on the surface of the ether, and also tends to produce 
suction at the space between the small central tube and the one 
which has the conical extremity, so that the ether passes through the 
hole in the side of the latter tube, rises in the space between the two 
tubes, and is forced as a jet of spray through the hole in the cone, 
and so on to the under surface of the plate I. This is roughened in 
the form of teeth for the purpose of presenting a large area to 
be acted upon, and also to facilitate drainage. A great deal of the 
ether drops down into the chamber, and is used again, but a little 
passes out mingled with the air in such a finely atomized condition 
that it seems impossible to collect it, and it is therefore conveyed 
along the tube H to the external air. 

The advantages of the new form are that all mess with ice and 
salt is avoided, that ether can always be kept at hand, and that 
inhalation of the vapour is limited to the short period during which 


* If the material is quite fresh the mucilage may be dispensed with, 


432 SUMMARY OF CURRENT RESEARCHES RELATING TO 


the chamber is being filled. The labour of pumping may be reduced 
by placing the ball-pump between two pieces of wood hinged like 
lemon-squeezers. Material has been frozen in a room at 96 F. using 
ether of +730 sp. gr. 


Swift and Son’s Improved Microtome.—In the microtome just 
described the sections are cut and their thickness regulated by the 
gradual descent of the knife towards the tissue to be operated upon. 
In order to reverse this process and provide a machine in which the 
tissue shall ascend towards the knife—as is the case in the ordinary 
form of section-cutters—Messrs. Swift and Son have brought out 
their new microtome, a drawing of which is given in Fig. 84, and which 


Fic. 84. 


is described as follows by Dr. S. Marsh in the new edition of his 
useful little work on section-cutting. 

“The instrument consists of a massive iron upright, terminating 
at its lower extremity in a clamping arrangement, by which it may be 
securely fastened to the table. From the top of the upright two highly 
polished iron bars, lying parallel to each other, run horizontally for- 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 433 


wards. These bars correspond to the cutting plate in the usual form 
of microtome, and upon them, as will be seen at A in the drawing, a 
flat brass frame carrying a knife is made to glide. The knife is kept 
firmly in position on this framework by means of the binding screw OC, 
the end of which, terminating in a square clamp, presses against the 
back of the blade. ‘The face of this clamp is grooved in different 
directions in such a manner that, according as the back of the blade is 
received into one or another of these grooves it is pushed from or 
drawn towards the level of the framework, thus affording a means by 
which the edge of the knife may be set at varying angles to the tissue 
to be cut. In front of the iron stand will be seen an angular upright 
pillar carrying in front of it a short length of sprung brass tube B, 
into which any of the apparatus presently to be described may be 
firmly fixed by a clamping screw. By means of a micrometer-screw 
E fixed at the base of the angular pillar, the sprung tube, and of 
course whatever it may carry, can be acted upon so as to raise or 
lower it at pleasure. The amount of movement thus effected is 
registered by the milled head of the screw, for which purpose three 
concentric circles have been drawn upon its face, each of which is 
so graduated that, as the face rotates from mark to mark, the distance 
traversed by the screw, and which of course determines the thickness 
of the section, will in the case of the outer circle be 1000th, in that 
of the middle 500th, and in the inner one 400th of an inch. The 
index by which these measurements are recorded consists of a spring 
catch so fitted that, as the milled head rotates, it drops into the 
divisions of the circles, into either of which it can be shifted at 
pleasure, or if desired can be thrown out of gear altogether. When 
it is intended to use the microtome for freezing with ether, the 
chamber provided for that purpose, and which in the engraving is 
shown in position, must be employed. This chamber is like the one 
already described when speaking of the Groves-Williams microtome, 
and consists of a reservoir for containing the ether and an upright 
cylinder leading from it, and terminating in a flat plate, upon which 
the object to be frozen lies. 'To use the machine, remove the cup D, 
fill the chamber with ether, then fix the cylinder in the clamp B, 
when the bellows F being worked the ether will project through the 
tubes in the interior of the chamber (which were described at p. 431), 
upon the plate holding the tissue, with the effect of speedily freezing 
it. When, under the action of the micrometer-screw, the object to 
be cut has moved upwards between the cutting bars sufficiently high 
for the purpose, sections are to be obtained by simply pushing the 
frame carrying the knife obliquely across the bars and through the 
tissue. For freezing purposes common methylated ether of a density 
of -720 answers perfectly well. In winter when ice is plentiful, and 
where only a very small piece of tissue requires to be frozen, the 
freezing may be effected without the employment of ether. For this 
purpose it will be necessary to use Dr. Pritchard’s solid freezer, 
Fig. 85. As will be seen, it consists of a solid metal block, having 
its upper surface, upon which the tissue to be frozen lies, roughened 
so as to prevent the specimen from slipping during section. For 


434 SUMMARY OF CURRENT RESEARCHES RELATING TO 


use, the block and tissue are frozen by being immersed in powdered 
ice and salt, then the block is secured in the clamp B, and sections 
cut in the manner just described. The microtome, though essentially 
a freezing one, may however be employed for cutting objects im- 
bedded in paraffin. For carrying out this, the box shown in Fig. 86 
has been provided. The tissue is to be imbedded in this box, and 
when the paraffin has become quite cold, the box must be secured 
in the clamp B and the tissue sectionized. 

“Yet another piece of apparatus belongs to this machine. It is 
called an adjustable vice, and is shown in Fig. 87. It is the most 
useful accessory, and there has long been a want felt for something 


Fic. 85. 


of its kind. It consists of a cylinder carrying at its upper end the 
two jaws of a vice. One of the jaws is fixed, whilst the other, being 
movable, may be made to recede from or approach to its fellow by 
means of the screw, so that hard substances of different kinds and 
various sizes may be securely fixed and held between the jaws, when, 
the cylinder being inserted in the clamp B, sections may be readily 
obtained. To the really working microscopist, this little appliance 
will be found of infinite value in a thousand directions. The uses 
of it are so obvious that no words will be wasted in describing them.” 

Though in this form, as in the others, the section knife, when 
in use, is mounted on a frame, no absolute necessity for its adoption 
exists, for the construction of the microtome permits of the use of 
an unmounted knife as readily as one mounted on a frame. The 
frame arranged has some advantages, particularly in retaining the 
keenness of the blade for a considerable period (coming into contact 
with nothing but the tissue) and in the confidence which it gives to 
the inexperienced operator. On the other hand, it renders the dis- 
engagement of the sections from the knife both a tedious and unsafe 
process, and Dr. Marsh is strongly of opinion, as the result of a very 
considerable amount of practical work, that in the hands of those who 
by careful practice have taught themselves how to use it, a simple 
unguarded knife is to be preferred to any mechanical arrangement 
whatever. 

Bausch and Lomb’s Standard Self Centering Turntable—We 
were unable to give at p. 284 any description of this turntable, but 
the following has since been supplied by Mr, E. Bausch. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 435 


The self-centering arrangement of the turntable is easily manipu- 
lated. The jaws are compressed by springs, and bear gently against 
the slide, so that, although it is firmly held, there is no danger of 
mutilating its corners or breaking it. One-sixth of a revolution of 
the milled ring is sufficient to open the jaws to their full extent, and 
as this is easily done with one hand, the other is free to place the 
slides. The hand-rest is detachable from the turntable. It has on 
its lower surface an adjusting screw for varying the distance from the 
revolving disk. 

For refinishing old slides, or others on which the object has not 
been well centered, a detachable pair of spring clips are provided. 


Concentric circles up to one inch diameter are turned on the 
disk. 


Crystallised Fruit Salt.*—Mr. G. J. Wightman says that Eno’s 
fruit salt, when crystallised, makes a magnificent polariscope object. 
The mode of preparation is as follows: In a small test tube, say 
3 X 2 inches, dissolve as much of the salt as would rest on a six- 
pence, by adding distilled water to the depth of an inch. With the 
end of a glass rod spread a few drops over an ordinary glass slip, 
and in a few minutes crystallisation will take place. The slide (with 
selenite) will be seen to be covered with numerous beautiful forma- 
tions, each somewhat resembling a Maltese cross made up of bril- 
liantly-coloured needle-like crystals. If it is held over the flame of 
a lamp as soon as the solution is placed on (so as to hasten crystallisa- 
tion), the colours will be the more splendid without selenite. Other 
beautiful effects may be produced by the addition of a few drops of 
alcohol to the test tube. The slides, as soon as dry, may be mounted 
in Canada balsam. 


AL.eEnN, F. J.—Cleaning Gizzards. 

[Feed the insects on honey, syrup, or treacle, before killing them.] 

Journ. Post. Micr, Soc., 1. (1882) pp. 48-9. 
ARNOLD, J. W. S.—Microscopical Laboratories. 

(Comments, &c., on the previous articles on the same subject—also as to 
the superiority of small instruments. ] 

Amer. Mon. Micr. Journ., III. (1882) pp. 69-70, 75. 
BAGuvT, Col.—Mounting Starches. 

[Not in balsam, but dry or in glycerine jelly, and viewed as opaque 
objects. ] 

Journ. Post. Micr. Soc., I. (1882) pp. 49-50. 
Birce, E. A.—On a Convenient Metliod of Imbedding. 

[Supr a, p. 428. ] 

Amer. Mon. Micr, Journ., II. (1882) pp. 73-5, 
Blood Stains on Steel. 

[Dr. M. C. White recognized and measured by means of the vertical 
illuminator and 1-ineh objective, blood-corpuscles upon a steel instru- 
ment that had been exposed during two winters in the woods. ] 

Amer. Natural., XVI. (1882) p. 347. 
Bowmay, F.. H.—See Cotton infra. 
Cuaton, Listes de préparations histologiques et botaniques de M. (List of 
histological and botanical preparations of M. Chalon.) 
Bull, Soc, Belg. Micr., VII. (1882) pp. liv.-vii. 


* Sci.-Gossip, 1882, p. 64. 


436 SUMMARY OF CURRENT RESEARCHES RELATING TO 


CuHEESEMAN, E. L.—Home-made Apparatus for Collecting. 

[ Bottle-holder to be attached to a stick made of a narrow strip of sheet 
brass, and an ordinary gimlet-pointed wood-screw with the head 
flattened. ] 

Amer. Mon, Micr, Journ., III. (1882) p. 61 (1 fig.). 
Coal-sections, Cutting. 
{Notes by A. Smith, E. Holmes, and W. D. Smith, on Mr. Kitton’s note 
infra—agreeing as to the failure of the carbonate of potash proce-s. ] 
Sci.-Gossip, 1882, pp. 113-4. 
Cotton Fibre, Structure of. 
[Review of Dr. F. H. Bowman’s book, ante, p. 119, with additional 
remarks. | 
Amer. Natural., XVI. (1882) pp. 431-2. 
Dyck, F. C. van.—Apparent Motions of Objects. 
Amer, Mon. Micr. Journ., ILI. (1882) pp. 72-3. 
Excocr, C.—How to Prepare Foraminifera. 

[For recent Foraminifera from sand, such as shore-gatherings, dredgings, 
&e.—1. Well wash in fresh water to remove the salt. 2. Dry perfectly, 
and allow to get cold. 3. Sift (sieve No. 50 or 60), 4. Float the fine 
material in cold fresh water. 5. Dry the floatings. Perhaps it may 
also be found needful to—6. Boil the floatings in liquor-potusse, B. P. 
7. Wash away every trace of potash. 8. Dry. 9. Re-float in a beaker. 
10. Dry again ready for mounting. ] 

Journ. Post. Micr. Soc., 1. (1882) pp. 25-9. 
Enock, F.—Metal Caps for Glycerine Mounts. 
Journ. Quek. Micr, Club, I. (1881) p. 40. 
FLEemine, J.—Mounting Volvox Globator in Glycerine Jelly. 

[After a month’s time the Volvor mounted in glycerine jelly, boiling, &e. 
in the usual way, ‘‘is perfect in form and colour, and the success of 
the attempt goes to prove that this Alga can be treated like any 
other, and may be boiled and pressed without the destruction of its 
shape.” 

ie North. Microscopist, If. (1882) p. 129. 
GorrscHav, —.—Mikrotomklammer fiir Keil- und plan-parallele Schnitte. 
(Microtome-clamp for wedge-shaped and plane sections.) 
SB. Phys.-Med. Gesell, Wirzbirg, 1881, pp. 123-5. 
Grarr, T. 8. U. pze.—Resolution of Fasoldt’s 18-band plate, and last band of 
19-band plate. 

[ Supra, p. 416.] 

Bausch § Lomb Optical Co.’s Supplement to Catalogue, Feb, 1882, p. 6. 
GREEN, J. H.—Cleaning and Mounting Gizzards. P 

[Kill the insect in spirit and leave for 3 or 4 weeks to harden. On 
opening the gizzard the loose particl:s of food or dirt can be washed 
out by Mr. Nicholson’s (infra) or other plans——Mount in slightly 
acidulated glycerine (not balsam) in a cell of gold-size.] 

Journ. Post. Micr, Soc., 1. (1882) p. 49. 
Groves, J. W.—Improved Ether Freezing Microtome. 

[osupra, p. 432.] 

Journ. Quek, Mier. Club, I. (1882) pp. 43-4. 
Marsh’s Microscopical Section-cutting, 2nd ed. 1882, pp. 60-8 (1 fig.). 
Harcu, H.—Microscopical Laboratories. 

[Remarks on article by Dr. J. W. Crumbaugh, ante, p. 287, who, he 
considers, desires to surround the student with too much and too 
expensive paraphernalia, discouraging him at the start.] 

Amer. Mon, Micr, Journ., III. (1882) pp. 51-2. 
Hircucock, R.—Ruled Bands. 

[Supra, p. 415.] 

Amer, Mon. Mier, Journ., IIL. (1882) pp. 52-3. 

4 os Illumination and Resolution. 

[Directions for resolving Amphipleura pellucida—in many cases of failure 
the fault is entirely in the illumination. ] 

Amer. Mon, Micr, Journ., IIL. (1882) pp, 53-4. 


ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 457 


Hircucock, R.—Mounting. 

[General remarks as to mounting for “ busy professional men who value 
every moment of their time and who, not having learned any simple 
process for mounting, are discouraged from attempting it by the 
multiplicity of processes and cements given in the books.” ] 

Amer. Mon. Micr. Journ., IL. (1882) pp. 55-6. 
5s 3 Collecting. 

[Note on objects to be found in March—May, and suggestions for the 
novice in collecting. | 

Amer. Mon. Micr. Journ., U1. (1882) p. 77. 
Juema, J—On the Origin and Growth of the Eggs and Egg-strings in 
Vephelis, with some obseryations on the “Spiral Asters.” 

[Contains methods of investigation for (1) genital organs in fresh condi- 
tion, (2) sections of entire leech, (3) hardening ovaries and egg- 
strings, (4) section-cutting, (5) surface views of the ovary-wall, (6) 
examination of early changes in mature eggs. ] 

Quart. Journ. Mier. Sci., XXII. (1882) pp. 189-211 ( pls.). 
Kirron, F.—Cutting Sections of Coal. 

[Describes his failures with the process given under “Coal” in the 
‘Micrographie Dictionary’ (maceration in carbonate of potash), and 
inquiring for the experience of others.] 

Sci.-Gossip, 1882, p. 89. 
Korscue_t, E.—EHine neue Methode zur Conservirung yon Infusorien und 
Ameceben. (A New Method for Preserving Infusoria and Amcebe.) 
Zool. Anzeig., V. (1882) pp. 217-9. 
Kunz, —.—Cinnamon Oil for the Examination of Rough Minerals. 

[By applying a few drops of oil to the surface of a transparent mineral, 
the interior can be examined for inclusions, flaws, &c., without grinding 
the surface flat. Sand can thus be examined for inclusions under the 
Microscope. ] 

Amer, Mon. Micr. Journ., IT. (1882) p. 59. 
Liste, T.—Glycerine-jelly Mounts. 

[Remedy for failures caused by imperfect removal of superfluous jelly :— 
Apply a mixture of whiting or chalk and water about the consistency 
of cream, to absorb the jelly; dry and break off carefully.] 

Journ. Post. Mier. Soc., I. (1882) p. 49. 
MarcuaL, E.—Préparations microscopiques destinées a Jl’enseignement. 
(Microscopical Preparations for Teaching)—contd. 

[B. Compound Organs, Stems, Roots, Leaves, Flowers ; C. Cryptogams— 

‘Ferns, Mosses, Lichens, Algz, Fungi.] 
Bull. Soc. Belg. Micr., VII. (1882) pp. xlvi.—liv. 
Marsu, S.—Microscopical Section-cutting. A practical Guide to the pre- 
paration and mounting of sections for the Microscope, special prominence beiag 
given to the subject of animal sections. 2nd ed. 8vo, London, 1882, xi. and 156 
pp. and 17 figs. 
Marruews, J.—See Michael, A. D. 


Micuart, A. D., and Marrsews, J.—Polarized Light as an addition to 
Staining for Vegetable and Animal Substances. 
{Supra, p. 426.] 
Journ. Quek, Micr. Club, I. (1882) pp. 49-51. 
Nicuotson, A.—Cleaning Gizzards. 
[Open and place in water for a day or two, and clean by agitating the 
water strongly by blowing through a pipette. ] 
Journ. Post. Micr. Soc., I. (1882) p. 49. 
Nosert’s Ruling Machine. 
[A query as to its construction, &c., by Akakia. } 
Engl. Mech., XX XY. (1882) p. 227. 
NorD.incer’s Wood Sections. 
{Transverse sections of the most important and most common trees. ] 
North. Microscopist, II. (1882) p. 130. 


438 SUMMARY OF CURRENT RESEARCHES, ETC. 


OLLARD, J. A.—Micro- Fungi. 
(Short note as to mounting. ] 
Engl. Mech., XX XV. (1882) p. 201. 
PritzNer, W.—Nervenendigungen in Epithel (Nerve-endings in Epithelium). 
(Contains description of methods, pp. 731-2.] 
Morphol. Jahr., VIL. (1882) pp. 726-45 (1 pl.). 
Pigeon-post Films. 
(Offer of gelatine films used for transmission of news by pigeon post 


during the siege of Paris.] 
Amer, Natural., XVI. (1882) p. 347. 
Pocgitincton, H.—The use of Staining Fluids in Vegetable Microscopy. 

[Résumé of various processes. ] 

Engl. Mech., XX XV. (1882) pp. 210-2. 
Scuréper’s Microtome for Cutting Sections of Diatoms, &e. 

[A query as to its practical success, by Akakia. ] 

Engl. Mech., XX XV. (1882) p. 227. 
Snow Crystals. 

(Query by T. Pearson as to the best way to examine them, “as they 

melt even in a room where there is no fire.] 
Sci.-Gossip, 1882, p. 114. 
Sorpy, H. C.—Preparation of Transparent Sections of Rocks and Minerals. 
(In part.) 
es [Account of the method he originally adopted for rock sections when 
“ everything had to be learnt, and there were then none of the facilities 
you have now.’’} 
North. Microscopist, II. (1882) pp. 101-6. 
TrEasDALE, W.—G. Chantrill’s Method of keeping objects alive for many 
months. 

[A number of zine shelves kept under a bell-glass, the requisite supply 
of moisture being provided by a quantity of thick felt kept constantly 
saturated.] 

Journ, Quek. Micr, Club, I. (1882) p. 41. 
UnveErui11, H. M. J.—Cleaning Gizzards. 

(Soaking in potash for a day.} 

Journ. Post. Micr. Soc., I. (1882) p. 48. 
oe == —Glycerine-Jelly Mounts. 

[Washing superfluous jelly off with a tooth-brush under water is a 
simpler method than Lisle’s (supra). Varnish must be applied within 
lialf an hour after cleaning or the jelly shrinks from the edge. 

Journ. Post. Micr. Soc., I. (1882) p. 49. 
“ Votvox.’’— Microscopy. 

{Examining circulation of blood in a tadpole’s tail. Take a hollow 
slide, or make a little trough by cementing four little strips of glass 
on a 3 x 1 slip so as to make a shallow cell. After placing the 
tadpole on its side in the cell and covering with water, drop a very 
small quantity of chloroform over its head. There is then “no pain 
to the tadpole nor risk of bruising it as when it is put under pres- 
sure, and should too much chloroform have been given it could not 
die in an easier way.”] 

Engl, Mech., XXXV. (1882) pp. 216-7. 
Wuite, T. C.—On the Injection of Specimens for Microscopie Examination. 

{Describes the process of making transparent injections of a small 
Mammal with cold injection fluid (Beale’s blue fluid), mounting in 
weak glycerine and camphor- water, and not in balsam or dammar, 
which would show nothing beyond the injected vessels, all the sub- 
structure which bears an intimate relation to the vascular arrange- 
ment being obliterated. Criticism of Dr. Carpenter’s recommendation 
of injections by professional mounters. } 

Journ. Quek. Micr, Club, I. (1882) pp. 15-9. 
Wixton’s (E. W.) Pond Life. 

[Intended supply of living objects.) 

Sci.-Gossip, 1882, p. 90. 


PROCEEDINGS OF THE SOCIETY. 


Mertine or 127TH Aprin, 1882, ar Krna’s Cotiece, Stranp, W.C., 
Tue Prestpent (Proressor P. Martin Dunoan, F.R.S) mw 
THE CHAIR. 


The Minutes of the Meeting of 8th March last were read and 
confirmed, and were signed by the President. 


The List of Donations (exclusive of exchanges and reprints) 
received since the last meeting was submitted, and the thanks of the 
Society given to the donors. 


From 
Loew, O., and Bokorny, T.—Die Chemische Kraftquelle im 
lebenden Protoplasma. viii. and 78 pp. (1 plate). 8vo, 
Witen@ ein, Wee: oo, co ba do ee oe oes oo be. PU OL eye 
Micrographic Dictionary. 4thed. Parts 8,9,and10 .. .. Mr. Van Voorst. 
Postal Microscopical Society—Journal, vol. i.No.1.. ..  .. The Society. 


Mr. M. M. Hartog (of Owens College) described some specimens 
which he exhibited. One of these was a living larva of Apus cancri- 
formis, the largest of the water fleas, the specimen shown having 
been bred this spring from some mud received from Germany. The 
other exhibits were a series of sections of Entomostraca which had 
been prepared for histological study. The specimens were killed by 
adding a few drops of osmic acid to the water in which they were 
placed, and as soon as they fell to the bottom they were sometimes 
removed to spirit direct; this plan had its advantage inasmuch as 
any mutilation was thereby avoided, but on the other hand by opening 
them in the osmic acid a certain amount of maceration was avoidable, 
which might in the former case prove to be detrimental to the 
histological structure. They were first transferred to 30 per cent. 
spirit, and then to 50 per cent., after which they were placed in 
cochineal solution in 70 per cent. alcohol and washed repeatedly in 
clean 70 per cent. alcohol until they gave up no more colour. After- 
wards they were placed in 90 per cent., and then in absolute alcohol. 
They were next treated after Giesbrecht’s method, with a greasy 
medium, and for this purpose whilst they were in the absolute 
alcohol a small quantity of oil of cloves was poured in, this sank to 
the bottom of the tube, and the Entomostraca would then lie not at 
the bottom but just between the alcohol and the oil of cloves, which 
gradually replaces the alcohol. In this way, with specimens which 
had been unopened, he had obtained preparations in which there had 
been absolutely no shrinkage of the protoplasm. Most of the oil of 
cloves was poured away and the specimens having been imbedded in 
a mixture of spermaceti and castor oil, the sections were cut in the 
usual way. It would be noticed that the sections were arranged in 
series on the slide. By this means of preparation he had been able 
to make out some important points. ‘The specimens exhibited 


440 PROCEEDINGS OF THE SOCIETY. 


(sagittal sections) the entire organs of the body, the nervous cord 
could be well seen, as could also the gullet with its muscles. A 
rough sketch was made on the slate to illustrate the chief points of 
interest. 

Mr. Beck thought the remarks of Mr. Hartog were exceedingly 
interesting, for if they were ever really to understand these structures 
it must be by means of sections. He was glad to have heard the very 
practical remarks which had been made, and hoped they would be 
the means of inducing others to practise the process, feeling sure 
that such a study would elucidate many points which were now 
involved in mystery. 

Mr. Stewart inquired whether in cutting the sections a microtome 
was used, or whether they were cut by hand. It also occurred to him 
that this process might be very useful in the preparation of sections 
of many of the soft-bodied creatures such as the mites or the Arach- 
nida, for it was very difficult to make out many parts of their anatomy 
by any process of dissection. 

Mr. Hartog, in reply, said that in all cases where sections had to 
be cut in series a microtome was necessarily used in order to secure 
perfect regularity of thickness. Zeiss’s microtome was the one he had 
employed, using oil to moisten the razor. He agreed that the process 
would be very useful in the case of mites and spiders, but he thought 
it well to remark that picric acid—so much in fayour for some 
purposes—should be avoided, as it penetrated too freely and caused 
the soft tissues to shrink from the chitinous body-wall. 


Mr. Crisp called attention to two Microscopes which he had 
brought for exhibition ; one of these, made in Dundee—which it had 
been proposed to call the “ Jumbo” Microscope—stood 4 feet high, 
with a tube 4 inches in diameter, and weighed about 13 cwt. It must 
have been made about 50 years ago. The other (the “ Midget”) 
made by Mr. 8. Holmes—shown by way of contrast—was completely 
finished for use, its entire height being only 3 inches, and its weight 
only a few ounces. Six of such Microscopes could be enclosed in 
the eye-piece of the larger one. He also exhibited the “ Acme” 
Class Microscope (see p. 251), and Browning’s Portable Microscope 
(see p. 252). 

Mr. Beck examined the large instrument and made some remarks 
as to the peculiarity of its construction. 


Dr. Loew’s note as to the chemical difference between living and 
dead protoplasm was read, and a photograph exhibited illustrating 
his and Bokorny’s statement as to the different reaction of dead and 
living protoplasm on silver salts (see I. (1881) pp. 906-7). 

Mr. A. W. Bennett said that the photograph represented two fila- 
ments of Spirogyra: nitida, One of these had been subjected in a 
living condition to the silver reagent, and the reducing effect of the 
living protoplasm had converted the cell-contents into a black opaque 
mass. The other filament had been killed by a 1 per cent. solution 
of citric acid before treatment with the silver solution. In this case 


PROCEEDINGS OF THE SOCIETY. 44] 


no reduction and consequent blackening is exhibited, the spiral 
arrangement of the chlorophyll-bands being still perfectly distinct. 

Mr. Stewart said he did not see that they had any actual proof 
that the protoplasm in the one case was dead and in the other living, 
especially when it was borne in mind that the way in which it was 
killed was by means of citric acid, a small residual quantity of which 
he thought might have some effect upon the result. 

Mr. Bennett said it was clear that they wanted more particulars 
before coming to a definite conclusion, though it was naturally to be 
supposed that all acid had been remoyed before the tests were 
applied. 

Mr. Hartog referred to the silver staining processes recently 
described in the Journal. 

Mr. Stewart said if they wanted to make silver staining a test in the 
case of the tissues of living animals it would not always be found an 
easy thing to do. In cases of operations they could probably get living 
tissues, but there were many parts which it would be very desirable to 
test with, which could not be obtained until after twenty-four hours 
from time of death, and yet he thought that in such cases the outlines 
of a cell were as perfectly rendered as if they were living. He was 
afraid that unless the citric acid were entirely eliminated, it would 
probably exercise an important influence on the results. 

Dr. Matthews felt sure that such would be the case, for it was 
well known that in photography the developing fluids had been 
acidified—and this especially by citric acid—for the purpose of 
retarding the reduction of the silver salt, so that the results where 
acid had been concerned would be very suspicious. The use of 
alkaline instead of acid preparations was the secret of the modern 
rapid processes of photographic development. 


Mr. Crisp referred to the views of Prof. Grunow on W. Prinz’s 
paper on Diatoms in Thin Rock Sections (see p. 246). 


Mr. Ingpen read a note on the use of diaphragms, illustrating his 
remarks by drawings upon the black-board. The ordinary wheel of 
diaphragms in general use was, he considered, effective only to a 
certain extent; and he gave the preference very decidedly to the 
sliding cylinder-diaphragm so largely adopted on the Continent, 
which was in fact a modification of that devised many years ago by 
Varley, in which double cylinders were used, one working within the 
other. The outer one had a moderate-sized opening sliding up in 
the substage, or in the ring provided for the purpose beneath the 
stage, until in contact with the slide. This cylinder was lined with 
cloth, to facilitate the sliding of the second cylinder, having a similar 
opening in the cap. By the proper use of this double cylinder the 
cone of light could be modified in the most perfect manner,—in fact 
it left nothing to be desired. The plate of diaphragms devised by 
Dr. Anthony, consisting of a series of apertures in a strip of vellum, 
to be placed immediately beneath the slide upon the stage, did not 
appear to him effective, inasmuch as at the position in which it was 

Ser. 2.—Von. II. 2G 


4412, PROCEEDINGS OF THE SOCIETY. 


placed, the cone of rays was far too small to be affected by the size of 
apertures adopted, passing, in fact, completely within the apertures. 
He might apply the same remarks to the action of the calotte dia- 
phragms, which he regarded as based on a wrong conception of the 
action of diaphragms, He could not commend the iris diaphragm on 
the ground that it required a special fitting, and could rarely be used 
near enough to the slide. 

Mr. J. Mayall, jun., said there was another purpose in the appli- 
cation of diaphragms, not touched upon in Mr. Ingpen’s remarks, 
namely, the cutting off different portions of the illuminating pencil. 
The mere cutting down the diameter was the main object of the 
wheel of apertures in common use, and of the cylinder diaphragms 
referred to, but Dr. Anthony’s diaphragm was intended to supplement 
the action of the strictly central aperture by a series that could be 
easily applied to cut off more or less of the beam after all had been 
done that was possible in modifying the light with the central aper- 
tures,—to use a phrase of Dr. Anthony’s, “ to give the finishing touch 
to the illumination.” Regarding the calotte diaphragm, its application, 
as a diaphragm alone, immediately beneath the slide, was due to Mr. 
Zeiss, who was hardly likely to have adopted it unless he had found 
it effective. The still more recent application of it above the con- 
denser must be regarded as a step in advance. Mr. Bulloch, of 
Chicago, appeared to be one of the earliest to see that the diaphragms 
beneath the optical combination in Gillett’s condenser, might be ad- 
vantageously applied above the lenses, where the cone of rays is so 
short and of such great angular extension that every variation in size 
or shape in the apertures of the calotte would be effective. Mr. Switt 
had also adopted the calotte in connection with the achromatic con- 
denser. The iris diaphragm was effective for low powers, especially 
when mounted to fit in the stage itself, as adopted by Messrs. Ross ; 
but he had not been satisfied with it in connection with the achromatic 
condenser. He believed there were difficulties in the construction 
which rendered it almost impossible to close the aperture with suffi- 
ciently accurate centering to be of real service with the condenser. 
In conclusion, Mr. Mayall said that the great number of devices 
that had been brought forward in recent years to cut off portions of 
the illuminating pencil independently of the mere reduction of the 
cone by strictly central apertures, proved conclusively that a need 
was felt in that direction. 

Mr. Beck said that though there might be differences of opinion 
as to what was the most valuable kind, he thought no one would 
dispute the great importance of a good diaphragm, which was of 
extreme value in rendering visible portions of an object which other- 
wise could not be seen. 

Mr. Ingpen said that his remarks were merely taking things as 
they stood, and did not, of course, apply to the use of the calotte dia- 
phragm with the achromatic condenser. The calotie diaphragm, as 
drawn by Mr. Mayall, was very effective, but almost every effect could 
be obtained by a very small number of stops with tolerably small 
apertures. Professor Abbe had satisfied himself of this entirely. 


PROCEEDINGS OF THE SOCIETY. 443 


The President read a note on the histology of the Temno- 
pleuride, which he illustrated by drawings upon the black-board. 

Mr. Stewart called attention to a curious change which took place 
under certain circumstances in the reticulated network ; where there 
was any friction going on it was found that the interstices became 
filled up with carbonate of lime, and this seemed to be a case of pre- 
cisely the same kind as what went on in bone-tissues under similar 
circumstances. Besides the spicules in the hard tissues there was 
found a remarkable exception in the structure of the teeth, which 
more closely resembled silicious rather than calcareous spicules. 

Mr. Hartog said that in studying the structure of these organisms 
it was important to study the soft parts in connection with the hard 
ones. To do this the specimen should be first stained and then 
saturated with liquid Canada balsam, which should be evaporated 
down to a resin: sections could then be cut through the shell and the 
soft parts, at the same time showing them together in situ, and stained 
as far as they could be. 

Mr. Stewart said that in Koch’s method it was solid copal varnish 
which was used instead of solid Canada balsam, the latter being too 
brittle to enable good sections to be cut. He had seen sections which 
had been made by this method, and they certainly showed the structure 
remarkably well in the corals, &e. 

The President said that Koch’s method was a most excellent one 
as applicd to corals, but it did not answer so well for Echinoderms. 
He had found it a very good plan to dissolve out the calcareous 
portions with weak acid. With regard to the fossil forms they all 
knew that the reticulated structure was entirely lost during fossili- 
zation, when it seemed entirely filled up by calcite. 

Mr. Stewart remarked that this complex network showed under 
the polariscope a common axis of tension passing through the entire 
body. 


Professor Abbe’s paper “On All-round Vision” was read by 
Mr. Crisp. 


The following Instruments, Objects, &c., were exhibited :— 

Mr. Crisp:—(1) “Jumbo” Microscope; (2) “ Midget” Micro- 
scope; (8) “Acme” Class Microscope (see p. 251); (4) Browning’s 

Portable Microscope (see p. 252). 

Mr. Hartog:—Apus cancriformis and a series of sections of 
Entomostraca. 

Mr. Ingpen :—Zeiss Microscope and sliding cylinder-diaphragms. 

Dr. Loew :—Photographs of Spirogyra nitida. 

Baron Ferd. v. Mueller, K.C.M.G., &c.:—Various dried Algz 
from the Phytologic Museum of Melbourne. 

Mr. L. A. Sillem :—Foot of Emerald spider. 


New Fellows.—The following were elected Ordinary Fellows :— 
Messrs. John A. Ollard, Henry Palmer, and Henry Pocklington. 
Honorary Fellows :—Professor C, Robin and Dr. L. Dippel. 

2G 2 


444 PROCEEDINGS OF THE SOCIETY. 


CONVERSAZIONE. 


The Second Conversazione of the Session was held on the 26th 
April in the Libraries of King’s College, when the following objects, 
&c., were exhibited :—- 

Mr. J. Badcock: 
Fredericella sultana and Epistylis sp. 
Mr. C. Baker: 

Preparations from the Zoological Station, Naples. 
Messrs. R. and J. Beck: 

Section of Leech and International Microscope. 
Mr. Thos. Bolton : 

Fredericella sultana. 

Mr. W. G. Cocks: 
Lacinularia socialis. 
Mr. Crisp: 

Various Schizophytes mounted by Dr. Zimmermann, of Chemnitz. 
Mr. H. Crouch: 

New Portable Microscope, and Siddall’s stage for use with 

ordinary selenites. 
Mr. Thos. Curties: 
Section of Triton, and larva of Synapta. 
Mer, ..T. Draper: 

Portfolio of drawings of microscopical objects. 
Mr. L. Dreyfus : 

Argulus foliaceus. 

Mr. F. Enock : 

Heads of bees showing all the organs of the mouth in their 
natural form and colour. Cédipoda cruceata, one day old; 
born in England from eggs sent from Troy. 

Mr. F. Fitch: 

Ventral cords of blow-fly from thoracic ganglion to end of 

abdomen and ramification. 
Mr. C. J. Fox: 

Diffraction effects produced by rectilinear and circular gratings. 
Dr. H. Gibbes: 

Human epididymis with spermatozoa in the tubes; section of 
mammalian kidney showing ciliated epithelium in the con- 
voluted tubes, and cerebellum injected and treble stained, 
showing cells of Purkinge and nerves proceeding from them. 

Mr. N. E. Green: 
Pleurosigma formosum by side and transmitted light, and Notting- 
ham deposit by side light. 
Mr. J. Hood : 
Cristatella mucedo. 
Mr. Joshua: 
Ceramium acanthonopum showing tetraspores, and Hydrurus pen- 
cillatus sent from Norway by Dr. O. Nordstedt. 
Mr. A. D. Michael : 

Pachygnatha de Geerti showing accessory sexual organs, and 

Tenuipalpus spinosus. 


PROCEEDINGS OF THE SOCIETY. 445 


Dr. Millar: 
Rectangular network of Dendispongia Steerii. 
Mr. C. N. Peal: 

Experiments illustrating the effect of various kinds of illumina- 
tion upon the appearances of diatoms. Micro-photographs of 
diatoms by Mr. J. H. Jennings, of Nottingham. 

Mr. B. W. Priest: 
Arachnoidiscus japonicus in situ. 
_Mr. J. W. Reed: 

Crystalloids in Lathrea squamaria and in the seed of Ricinus 

communis. 
Mr. A. Sanders: 

Stained sections of the brain of Hyperopisus dorsalis, a fish 

belonging to the family Mormyride. 
Mr. Sigsworth : 
Double platino-cyanide of magnesium and yttrium of various 
forms. 

Mr. L. A. Sillem : 

Volkeria pustulosa, plates of star-fish, &c. 
Mr. George Smith : 

Section of meteorite (U.S.A.). 
Mr. James Smith: 

Aphides of rose and nettle. 
Mr. J. H. Steward : 

Pleurosigma angulatum with 545 immersion object-glass by Hen- 
soldt, Meteorite showing fluid cavities, &c. 

Mr. A. W. Stokes: 
Combustion and volatilization of zine, copper, iron, &ec., in the 
electric are under the Microscope. 
Mr. H. J. Waddington : 
Stephanoceros and Melicerta. 
Mr. F. H. Ward: 

Section of stems of Jasminium nudiflorum and Ampelidea double 

stained. 
Mr. E. Wheeler: 

Ruby and ruby sand section of meteorite showing cavities with 
liquid or gaseous contents ; new Diatomacez from Hong Kong, 
&e. 

Mr. T. C. White: 
Rectal papille of blow-fly and earwig. 
Messrs. J. Swift and Son : 

Podura scale with student’s } object-glass on improved American 

Microscope. 


Meetine or 10TH May, 1882, at Kine’s Cottecn, Stranp, W.C., 
James GLAIsHER, Esq., F.R.S., In THE CHAIR. 


The Minutes of the Meeting of 12th April last were read and 
confirmed, and were signed by the Chairman. 


446 PROCEEDINGS OF THE SOCIETY. 


The List of Donations (exclusive of exchanges and reprints) 
received since the last meeting was submitted, and the thanks of the 
Society given to the donors. 

From 
Blades, W.—The Enemies of Books. 3rd ed., 1881 Prof. A, Liversidge, F.R.S. 
Geological and Natural History Survey of Canada. Report of 

Progress for 1879-80. (8vo, Montreal, 1881).. Government of the Dominion, 
Hermann, L.—Handbuch der Physiologie. Vol. iv. Part 2. viii. 

and 467 pp., 58 figs. (8vo, Leipzig, 1882) .. .. .. .. Mr. Crisp. 
Micrographic Dictionary, Part 11 SS So 46, . Mr. Van Voorst. 


Mr. Crisp read letters from Professor C. Robin and Dr. L. Dippel 
in acknowledgment of their election as Honorary Fellows. 


Mr. Dowdeswell read a paper on “The Bacteria of Davaine’s 
Septicemia ” (see p. 310). 

The Chairman said he was very glad that they had had a paper 
on so important a subject. Observations upon Bacteria were daily 
acquiring more and more value, from their supposed connection with 
various kinds of disease. He hoped that Mr. Dowdeswell would con- 
tinue his observations upon the subject, and that he would be able to 
explain the great discrepancies which he had observed to exist between 
the size of the specimens he had described and those which had been 
referred to by other observers. 


The Chairman referred to a letter received from Mr. Ralph, the 
President of the Victoria (Australia) Microscopical Society, in which 
he mentioned that he expected to be present that evening. At the 
last moment, however, he had been prevented from coming. He was 
sure they would all hope that Mr. Ralph would be in England at 
their next meeting, so that they might welcome him both as one of 
their ex-officio Fellows and also as the representative of almost the 
only Colonial Microscopical Society. 


Mr, Burnett's note on a new form of rotating live-box was read 
and the apparatus exhibited (see p. 410). 


Mr. Sigsworth exhibited a spring paper-clip which he had found 
very useful in fastening card cells upon slides and much more con- 
venient for the purpose than the so-called “ American” clips. 


Dr. Van Heurck’s views on the use of the incandescent electric 
light for microscopy were briefly referred to by Mr. Crisp, who ex- 
plained, by means of black-board drawings, two cases in which, in 
consequence of its superior intensity, the electric light might be made 
use of to extend somewhat the resolving power of an objective. Dr. 
Van Heurck had recently obtained an improved form of battery which 
superseded the one he originally described. He found the Swan form 
of lamp to be the most suitable for microscopical work (see p. 418). 


Professor Abbe’s paper “ On the Relation of Aperture and Power 
in the Microscope,” Part I. (see p. 300), was read by Mr. Crisp, who 


PROCEEDINGS OF THE SOCIETY. 447 


referred to the complete paper as being one of the most valuable 
and useful papers that had ever been brought before the Society, 
dealing as it did not only with the theoretical part of the subject but 
establishing also a rational standard for the practical construction of 
objectives. 

The Chairman considered that Professor Abbe’s paper was indeed 
a most useful one, and that it would be greatly appreciated by practical 
opticians. 

Mr. Beck said that he considered it was an exceedingly valuable 
paper, and one that would enlighten a great many persons as to the 
relative value of aperture and magnifying power in regard to which 
great confusion had existed. There were people who thought that if 
they could get a1-inch objective with an aperture of 120°, they could 
resolve difficult diatom tests. He had heard it claimed that such 
glasses had been made, but although he had ordered one he had not 
yet been able to get it, and hopes that might have been raised by 
these announcements would be damped by the contents of Professor 
Abbe’s paper. He was very glad that it had been written, because it 
had been his impression for some time that Professor Abbe had been 
working exclusively in the direction of wide apertures, 

Mr. Ingpen was surprised to hear Professor Abbe, of all persons, 
charged with an exclusive approval of large apertures, for if any one 
looked at Zeiss’s catalogue, they would see at once that all the dry 
lenses were of remarkably small angles, nothing exceeding 110°. 

Mr. Crisp said that the most opposite notions had been held as to 
Professor Abbe’s views on wide or narrow apertures. Some years 
ago it was stated, at one of the Society’s meetings, that he advocated 
only narrow apertures, and some correspondence took place in regard 
to it in the ‘ Monthly Microscopical Journal.’ Again, later, it was 
insisted that Professor Abbe considered all but wide powers useless 
to the microscopist! The fact was that Professor Abbe had, since 
the date of his earliest observations on aperture, advocated the main- 
tenance of a proper ratio between aperture and power—wide apertures 
for high powers, and small apertures for low powers—and had 
always insisted on the great importance of perfecting the construction 
of moderate apertures. The confusion had arisen from the fact of 
Professor Abbe having shown, in connection with his theory of micro- 
scopical vision, that wide apertures, and wide apertures only, gaye 
true images of minute objects; but it did not, of course, follow from 
that, that wide apertures were to be universally used, with low powers 
and with objects unsuitable, either from their requiring depth of 
vision or for other reasons. 


‘Mr. J. Mayall, jun., exhibited Ross’s “ Hospital Microscope,” 
the speciality of which is the fine adjustment, which is of simple 
construction. 


Dr. Maddox read a paper “ On Some Micro-organisms from Ice- 
Water and Hail,” illustrated by a number of photo-micrographs. 
The Chairman inquired how Dr. Maddox accounted for the exist- 


448 PROCEEDINGS OF THE SOCIETY. 


ence of the organisms which he had described. Did they come from 
the atmosphere ? 

Dr. Maddox thought that with regard to those from the ice of the 
water-butt, they probably were in the rain-water before it froze, and 
they alone survived; those found in the water from melted hail most 
likely came down from the atmosphere with the hail. 


Prof. F. J. Bell’s paper, “Note on the Spicules found in the 
Ambulacral Tubes of the regular HEchinoidea” (see p. 297), was, 
owing to the lateness of the hour, taken as read. 


The following Instruments, Objects, &c., were exhibited :— 
Mr. Burnett :—New form of Rotating Live-Box (sce p. 410). 
Mr. Dowdeswell :—Bacteria illustrating his paper (see p. 310). 
Dr. Maddox :—Photo-micrographs illustrating his paper. 

Mr. J. Mayall, jun. :—Ross’s Hospital Microscope. 

Mr. Sigsworth :—Spring clip. 


New Fellows.—The following were elected Ordinary Fellows :— 
Messrs. T. 8. Up de Graff, M.D., John Inglis, J.P., Captain A. H. 
Southey, Prof. Ramsay Wright, and John Wright. 


Water W. Reeves, 
Assist.-Secretary. 


( 13) 


SR. & J. BECK, 


MANUFACTURING OPTICIANS. 


68, CORNHILL, LONDON, E.C. 
1016, CHESTNUT ST., PHILADELPHIA, U.S.A. 


FACTORY : 


LISTER WORKS, HOLLOWAY, LONDON, N. 


MICROSCOPES, 
MICROSCOPE OBJECT-GLASSES, 
PATHOLOGICAL AND 
PHYSIOLOGICAL PREPARATIONS, 


Materials and Instruments for Mounting 
Objects, and for Students’ Use. 


ILLUSTRATED CATALOGUES 


DESCRI PLIVE PAMPHLETS 


OF the Cheaper Forms of Microscopes forwarded upon 
| Application to 


es Re: 8ST. BECE, 
_ 68, CORNHILL, LONDON, E.C._ 


( 4 ) 
JOURNAL 


OF THE 


ROYAL MICROSCOPICAL SOCIETY, 


Containing its Cransacttions and Proceedings, 
AND A SUMMARY OF CURRENT RESEARCHES RELATING TO 


ZOOLOGY AND BOTANY 
(principally Invertebrata and Cryptogamia), 


MICROSCOPY, &e. 


Edited by 


Frank Crisp, LL.B., B.A., 


one of the Secretaries of the Society and a Vice-President and Treasurer of the 
Linnean Society of London ; 


WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND 


A. W. Bennett, M.A., B.Sc., F. Jerrrey Bet, M.A., 
Lecturer on Botany at St. Thomas’s Hospital, | Professor of Comparative Anatomy in King’s College, 


8. O. Rupuey, M.A,, of the British Museum, and Joun Mayatt, Jun., 
FELLOWS OF THE SOCIETY, 


Tus Journal is published bi-monthly, on the second Wednesday of the 
months of February, April, June, August, October, and. December. It 
varies in size, according to convenience, but does not contain less than 
8 sheets (128 pp.) with Plates and Woodcuts as required. The price to 
non-Fellows is 4s. per Number. 


The Journal comprises: 


(1.) The TRANSACTIONS and the ProcrEpines of the Society: 
being the Papers read and Reports of the business trans- 
acted at the Meetings of the Society, including any _ 
observations or discussions on the subjects brought 
forward. 

(2.) Summary of OurrENT Researcues relating to ZooLocy . 
and Borany (principally Invertebrata and Cryptogamia, : 
with the Embryology and Histology of the higher Animals 
and Plants), and Microscopy (properly so called): being = 
abstracts of or extracts from the more important of the =~ 
articles relating to the above subjects contained in the = 
various British and Foreign Journals, Transactions, a 
from time to time added to the Library. 


‘Authors of Papers printed in the Transactions are entitled to 20 copies 
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International Exhibition Prize Medals and Awards, 1851, 1855, 1862, 1873, 1878; and 


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M. PILLISCHER’S NEW MICROSCOPE, 
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( 18 ) - 
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Edited by ARTHUR C. COLE, F.R.MS., &., assisted by several Eminent Specialists. — 


* A-Weexty Perfopicar for the use of Students, Teachers, Professors, and the Medical Profession, and others 
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The terms of subscription, payable stictly in advance, including Postage, sre—In Great Britain, Quarterly, 
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( 19 ) 


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ESTABLISHED 18580. 


THE 


ROYAL MICROSCOPICAL SOCIETY. 


(Founded in 1839. Tneorporated by Royal Charter in 1866.) 


The Society was established for the communication and discussion 
of observations and discoveries (1) tending to improvements in the con- 
struction and mode of application of the Microscope, or (2) relating to — 
Biological or other subjects of Microscopical Research. eP 

It consists of Ordinary, Honorary, and Ex-officio Fellows. 

Ordinary Fellows are elected on a Certificate of Recommendation 
signed by three Fellows, stating the names, residence, description, &¢., of 
the Candidate, of whom one of the proposers must have personal know- 
ledge. The Certificate is read at.a Monthly Meeting, and the Candidate 
balloted for at the succeeding Meeting. 

The Annual Subscription is 2/. 2s., payable in advance on election, 
and subsequently on Ist January annually, with an Entrance Fee of 21. 2s, 
Future payments of the former may be compounded for at any time for | 
311.10s. Fellows elected at a meeting subsequent to that in February are 
only called upon for a proportionate part of the first year’s subscription, 
| and Fellows absent from the United Kingdom for a year, or permanently 
residing abroad, are exempt from one-half the subscription during absence. _ 

Honorary Fellows (limited to 50), consisting of persons eminent — 
in Microscopical or Biological Science, are elected on the recommendation 
of three Fellows and the approval of the Council. 

Ex-officio Fellows (limited to 100) consist of the Presidents for 
the time being of such Societies at home and abroad as the Council may — 
recommend and a Monthly Meeting approve. They are entitled to receive 
the Society’s Publications, and to exercise all other privileges of Fellows, 
except voting, but are not natires to pay any Entrance Fee or Annual 
Subscription. : 

The Council, in eo the management of the affairs of the Society 
is vested, is elected annually, and is composed of the President, four Bocas 
Presidents, Treasurer, two Secretaries, and twelve other Fellows. 

The Meetings are held on the second Wednesday in each cits ea? 
from October to June, in the Society’s Library at King’s College, Strand, shes 
_ WC, (commencing at 8 pt.) Visitors are admitted by the introduction of 

Fellows. : 
. In each Session two additional evenings are devoted to the exhibition’ Se NR 

of Instruments, Apparatus, and Objects of novelty or interest relating to re 
|. the Microscope or the subjects of Microscopical Research. ee ee 

~The Journal, containing the Transactions and Proceedings of the el eee 
Society, with a Summary of Current Researches relating to Zoology and | — 

Botany (principally Invertebrata and Cryptogamia), Microscopy, &e., is | — 
| published bi-monthly, and is forwarded gratis to all Ordinary and Ex-ofticio Pie St 
| Fellows residing in countries within the Postal Union. © ee 

The Library, with the Instruments, Apparatus, and Cabinet ee pin 
Objects, is open for the use of Fellows on Mondays, Tuesdays, Thursdays, ae 
and Fridays, from 11 A.m. to 4 P.m., and on Weanssieye. from 7 to 10 Par | 
It is closed during August. — apes 

Forms of proposal for Fellowship, and any further information, may be obtalehel id Se 


- : : application to the Secretaries, or ee ee at the bee ats od wer “ing A 
College, Strand, W.C. eben 


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